Okay, that was an admittedly "dark"-sounding title, but it's perfectly appropriate for today's topic...How to get- and keep- your water as tinted as possible. Or, at least, what materials would do the best job in terms of "color production."
We as a group are kind of obsessed with this.
And yeah, it's a good question!
Now, first off- let's all remember that the color of the water has absolutely NO relationship to its pH or carbonate hardness. It just doesn't. You can have water that looks super dark brown, yet has a pH of 8.5 or whatever. And conversely, it's just as possible to have crystal clear blue-white water that's soft, and has a pH of 4.5. We have to get beyond the social media-style "blackwater" definition, which seems to be, "If the water is tinted, it's a blackwater aquarium!"
Now, look, if you just want the nice color but could care less about the pH and hardness, that's fine. For the benefit of the hobby as a whole, please don't perpetuate the confusing narrative about blackwater aquariums by telling others that you have "blackwater." You have a "tinted" aquairum.
And that's just fine.
So, yeah-I'm not going to launch into a long drawn out description today about how ecologists define "blackwater" and what specific chemical characteristics make it up- we've covered it enough over the years...you can deep dive here or elsewhere to get that.
Okay, micro-rant over. Let's get back to the topic.
Remember, this piece is not about how to make blackwater...It's a little more superficial than that...it's about creating an aquarium with color and maintaining it.
First off, one of the "keys" to getting your color that lovely brown is to select the right types and quantities of botanical materials to assist. Now, I'll be the very first to raise my hand and call BS on anyone who claims to have a perfect "recipe" for how many Catappa leaves per liter or whatever you must use to achieve a specific color. Sure, you could come up with some generic recommendations, but they're not always applicable to every tank or situation.
Yes...there are simply so many variables in the equation- many which we probably haven't even considered yet-that it would be simply guessing. Just like Nature, to some extent...
What I can do is recommend some materials which we have found over the years to generally impart the most reliable and significant color to water. In no particular order, I'll give you my thought on a few of my personal faves. There are a lot more, but these are some that consistently show up on my "fave" list.
Yep, you heard me. One of the very best sources of tint-producing tannins in our aquariums is wood. I've told you many times, wood imparts tannins, lignin, and all sorts of other "stuff" from the exterior surfaces and all of those nooks and crannies that we love so much into the water.
Now, I don't know about you, but I'm always amused (it's not that hard, actually) by the frantic posts on aquarium forums from hobbyists that their water is turning brown after adding a piece of wood. I mean- what's the big deal?
Oh, yeah, not everyone likes it...I forgot that. 😂
The reality, though, as you probably have surmised, is that wood will continue to leach tannins to a certain extent pretty much for as long as it's submerged. As a "tinter", I see this as a great advantage in helping establish and maintain the blackwater look, and to impart humic substances that are known to have health benefits for fishes.
Some wood types, like Mangrove ( a wood we don't have at the moment), tend to release more tannins than others over long periods of time. Other types, like "Spider Wood", will release their tannins relatively quickly, in a big burst. Some, such as Manzanita wood, seem to be really "dirty", and release a lot of materials over long periods of time. All will recruit fungal growths and bacterial biofilms.
And the biocover on the wood is a unique functional aesthetic, too, as we rant on and on about here!
I'm a huge fan of tree bark to impart not only color, but beneficial tannins into the water. Because of its composition and structure, bark tends to last a very long time when submerged, and tends to impart a lot of color to the water over the long term.
And to be quite honest, almost all of the bark products we've played with over the years seem to work equally as well. The real difference in bark is the "form factor" (appearance) and the color that they impart to the water over time. Some, such as Red Mangrove bark or Cutch bark, will impart a much deeper, reddish-brown tint to the water than say, an equal quantity of catappa bark. And our soon-to-be-released Ichnocarpus bark really packs in this reddish brown color! You're gonna love this stuff!
Ounce for ounce, gram for gram, I've always felt that various types of bark always impart the most color to the water over almost any other materials.
These are very interesting, woody pods, derived from the outer "valve" of the fruit of the Swietenia macrophylla tree, which hails from a wide range of tropical locales (although native to Brazil), and are just the sort of thing you'd find floating or submerged in a tropical jungle stream. Often called "Skyfruit" by locals in the regions in which they're found because they hang from the trees- a name we fell in love with!
These botanicals can leach a terrific amount of tannins, akin to a similar-sized piece of Mopani wood or other driftwood. They are known to be full of flavonoids, saponins, and other humic substances, which have known positive health effects on fishes. Like bark, it lasts a good long time and recruits some biofilms and fungal growths for good measure.
Live Oak Leaves/Magnolia Leaves
Despite their humble North American origins, these leaf types impart more color, ounce per ounce, than just about any of our fave tropical leaves. And they both last very long time...Like, I've had specimens of live oak leaves stay intact for several months!
It's really important to think of leaves as not just a "coloring agent" for your water, but as a sort of biological support mechanism for your burgeoning ecosystem. They actively recruit fungi, bacterial biofilms, and other microorganisms which enrich the overall aquatic environment in your tank.
Alder cones (Aalnus glutinosa and Alnus incana) and Birch cones (Betula occidentalis), have been widely utilized by aquarium hobbyists in Europe for some time. Betta and ornamental shrimp breeders are fond of the tannins released into the water by these cones, and their alleged anti fungal and antibacterial properties. There has also been much study by hobbyists about the pH reduction attributes of these cones, too.
A study done a few years back by a Swedish hobbyist using from one to six cones in a glass containing about 10 ounces of tap water, with a starting ph of around 8.12, was able to affect a drop to 6.74 with one cone after about two weeks, 4.79 with 2 cones after two weeks, and an amazing 3.84 with 6 cones after the same time period! The biggest part of the drop in pH occurred in the first 12 hours after immersion of the cones!
Now, I'm the last guy to tell you that a bunch of cones is the perfect way to lower pH, but this and other hobby-level studies seem to have effectively have demonstrated their ability to drive pH down in "malleable" (soft) water...
Coconut-based products (Coco Curls, "Fundo Tropical", "Substrato Fino")
There's something about coconuts...The materials which are derived from the husks of coconuts seem to produce a significant amount of tannins and impart color to the water. Of course, "Substrate Fino" and "Fundo Tropical" are smaller, or finer-textured materials which work primarily as "substrate enhancers", and not strictly as "color-producing agents", because there is an initial "burst", which subsides over time.
Now, one of the novel applications for these finer botanical materials to take advantage of their color producing ability is to place them in a fine mesh filter bag and allow water to flow around or through them, like filter media. Essentially, a more sustainable alternative to the old peat moss trick...
For an interesting look and some nice color, I'm a big fan of oak twigs. Oak has a nice bark which imparts a deep brownish/yellow color to the water and it's quite distinctive. There is a reason why our "Twenty Twigs" packs are pretty popular, and it's not just because you get a bunch of cool sticks!
When mixed with leaves and/or other botanical materials, not only do you get an incredible "framework" for a cool ecosystem, you get an incredible aesthetic as well!
Now, this is an absolutely cursory list.. I could have easily listed 10 or more items. No doubt, some of you hardcore enthusiasts are screaming at your screens now: "WTF Fellman, you didn't include_______!"
And of course, that's the beauty of natural materials...There are numerous options!
Another note on the colors to expect from various botanical materials. As you might suspect, many of the lighter colored ones will impart a correspondingly lighter tint to the water. And, some leaves, such as Guava or Loquat, also impart a more yellowish or golden color to the water, as opposed to the brownish color which Jackfruit and Catappa are known for.
A lot of you ask about things that impact how long the water retains it's tint.
This kind stuff is a big deal for us- I get it! Many hobbyists who have perhaps added some catappa leaves, "blackwater extracts", or rooibos tea to their water contact me asking stuff like why the water doesn't stay tinted for more than a few days. Now, I'm flattered to be a sort of "clearing house" for this stuff, but I must confess, I don't have all the answers.
So, "Why doesn't my water stay tinted, Scott?"
Well, I admit I don't know. Well, not for certain, anyways!
I do, however, have some information, observations, and a bunch of ideas about this- any of which might be literally shot to pieces by someone with the proper scientific background. However, I can toss some of these seemingly uncoordinated facts out there to give our community some stuff to "chew on" as I offer my ideas up.
Now, perhaps it starts with the way we "administer" the color-producing tannins.
Like, I personally think that utilizing leaves, bark, and seed pods is perhaps the best way to do this. I'm sure that you're hardly surprised, right? Well, it's NOT just because I sell these material for a living...It's because they are releasing tannins, humic substances, and other compounds into the water "full time" during their presence in the aquarium as they break down. A sort of "on-board" producer of these materials, with their own "half life" (for want of a better term!).
And, they also perform an ecological role, providing locations for numerous life forms (like fungal growths) surface area upon which to colonize. They become part of the ecosystem itself. A few squirts of "blackwater extracts" won't do that, right?
The continuous release of tint-producing compounds from botanical materials keeps things more-or-less constant. And, if you're part of the "school" which leaves your botanicals in your aquarium to completely break down, you're certainly getting maximum value out of them! And if you are continuously adding/replacing them with new ones as they completely or partially break down, you're actively replenishing and adding additional "tint-producing" capabilities to your system, right?
There is another way to "keep the tint" going in your tanks, and it's pretty easy. Now, those of you who know me and read my rambling or listen to "The Tint" podcast regularly know that I absolutely hate shortcuts and "hacks" in the aquarium hobby. I preach a long, patient game and letting stuff happen in its own time...
Nonetheless, there ARE some that you can employ that don't make you a complete loser, IMHO.😆
When you prepare your water for water changes, it's typically done a few days to a week in advance, so why not use this time to your advantage and "pre-tint" the water by steeping some leaves in it? Not only will it keep the "aesthetics" of your water ( can you believe we're even talking about "the aesthetics of water?") consistent (i.e.; tinted), it will already have humic substances and tannins dissolved into it, helping you keep a more stable system.
Obviously, you'd still check your pH and other parameters, but the addition of leaves to your replacement water is a great little "hack" that you should take advantage of. (Shit, I just recommended a "hack" to you...)
It's also a really good way to get the "look" and some of the benefits of blackwater for your system from the outset, especially for those of you heathens that like the color of blackwater and despise all of the decomposing leaves and seed pods and stuff!
So, if you're just setting up a brand new aquarium, and have some water set aside for the tank, why not use the time while it's aging to "pre-tint" it a bit, so you can have a nice dark look from day one? It's also great if you're setting up a tank for an aquascaping contest or other same-day club event that would make it advantageous to have a tinted tank immediately.
I must confess that yet another one of the more common questions we receive here from hobbyists is, "How can I get the tint in my tank more quickly?"- and this is definitely one way!
How many botanicals to use to accomplish this?
Well, that's the million dollar question.
It all gets back to the (IMHO) absurd "recommendations" that have been proffered by vendors over the years recommending using "x" number of leaves, for example, per gallon/liter of water. There are simply far, far too many variables- ranging from starting water chem to pH to alkalinity, and dozens of others- which can affect the "equation" and make specific numbers unreliable at best.
We did, too, in the early days of Tannin. And it was kind of stupid really. There just is no hard-and-fast answer to this. Every situation is different. You need to kind of go with your instinct. Go slowly. Evaluate the appearance of your water, the behaviors of the fishes...the pH, hardness, TDS, nitrate, phosphate, or other parameters that you like to test for.
It's really a matter of experimentation.
I'm a much bigger fan of "tinting" the water based on the materials in the aquarium. Letting Nature have at it. The botanicals will release their "contents" at a pace dictated by their environment. And, when they're "in situ", you have a sort of "on board" continuous release of tannins and humic substances based upon the decomposition rate of the materials you're using, the water chemistry, etc.
Replacement of botanicals, or addition of new ones, as we've pointed out many times, is largely a subjective thing, and the timing, frequency, and extent to which materials are removed or replaced is dependent upon multiple factors, ranging from base water chemistry to temperature, to the types of aquatic life you keep in the tank (ie; xylophores like certain Plecos, or strongly grazing fishes, like Headstanders, will degrade botanicals more quickly than in a tank full of characins and such).
(The part where Scott bashes the shit out of the idea of using "blackwater extracts" and Rooibos tea. This could get nasty!)
If you haven't heard of it before, there is this stuff called Rooibos tea, which, in addition to bing kind of tasty, has been a favored "tint hack" of many hobbyists for years. Without getting into all of the boring details, Rooibos tea is derived from the Aspalathus linearis plant, also known as "Red Bush" in South Africa and other parts of the world.
(Rooibos, Aspalathus linearis. Image by R.Dahlgr- used under CC-BY S.A. 2.5)
It's been used by fish people for a long time as a sort of instant "blackwater extract", and has a lot going for it for this purpose, I suppose. Rooibos tea does not contain caffeine, and and has low levels of tannin compared to black or green tea. And, like catappa leaves and other botnaicals, it contains polyphenols, like flavones, flavanols, aspalathin, etc.
Hobbyists will simply steep it in their aquariums and get the color that they want, and impart some of these substances into their tank water. I mean, it's an easy process. Of course, like any other thing you add to your aquarium, including leaves and botanicals, it's never a bad idea to know the impact of what you're adding.
Like using botanicals, utilizing Rooibos tea bags in your aquarium requires some thinking, that's all.
The things that I personally dislike about using tea or so-called "blackwater extracts" are that you are simply going for an effect, without getting to embrace the functional aesthetics imparted by adding leaves, seed pods, etc. to your aquarium as part of its physical structure and ecology, and that there is no real way to determine how much you need to add to achieve______.
Obviously, the same could be said of botanicals, but we're not utilizing botanicals simply to create brown water or to target specific pH parameters, etc. We're trying to create an ecology that is similar to what you'd see in such habitats in Nature.
Yet, with tea or commercial blackwater extracts, you sort of miss out on replicating a little "slice of Nature" in your aquarium. The building of an ecosystem. Which is why we call this the botanical method. It's not a "style" of aquascaping! And of course, it's fine if your goal is just to color the water, but it's more of an aesthetically-focused aquarium at that point.
I also understand that some people, like fish breeders who need bare bottom tanks or whatever- like to condition water without all of the leaves and twigs and nuts we love. They want the humic substances and tannins, but really don't need/want the actual leaves and other materials in their tanks.
And, when it comes to tea and these commercial extracts, I don't think the stuff lasts all that long. I personally believe that the tint-producing tannins in "tea" are potentially taken up quickly by substrate materials, filter media, etc. And unless you're keeping tea bags in your tank on a continuous basis, you'll always experience some "color loss" after some period of time.
Yes it works to impart some color and tannins. Creating infusions or extracts is useful, if you understand their purpose and limitations. They have a place in the hobby for sure.
It's why we got into the game with our botanical-based "Shade" products. We're currently sold out and are working with our supplier on a reformulated version. Seems as though we need to make a "darker" mix!
On the other hand, if you're trying to replicate the look and function (and maybe some of the parameters) of THIS:
You won't achieve it by using THIS:
It's simply another shortcut.
Not good or bad. Just a way to get the end "effect" faster, and without the other collateral benefits we discussed.
And look, I understand that we are all looking for the occasional shortcuts and easier ways to do stuff. And I realize that none of what we proffer here at Tannin is an absolute science. It's likely more of an "art" at this point, with a little science behind it.
Think about it: There is no current way available to the hobby to test for "x" types or amounts of tannins (of which there are hundreds of types) in aquariums. I mean, there are tannin test kits, but they're used for wine making and such...Perhaps there is some tangential application for our purposes, but I'm not really sure what practical information. we could extract from the results.
And, I have not found a study thus far which analyzed wild habitats (say, Amazonia) for tannin concentrations and specific types, so we have no real model to go on.
The best we can do is create a reasonable facsimile of Nature.
And, in Naturę, a lot of the tint in blackwater environments comes from dissolved fulvic and humic acids from...soils. Yeah, geology is the key, IMHO, to truly "realistic" blackwater habitats. This is why I've been very picky on sourcing the materials and figuring out recipes for our NatureBase sediment substrates. They are intended to support these types of systems.
Understanding substrates and their role in both the physical environment and the ecology of our aquariums is still a wildly under-appreciated concept in the aquarium hobby, IMHO. We'll keep coming back to this in the future, I'm certain.
And keeping the water tinted is something that many botanical method aquarists are interested in. This wonderful "collateral benefit" of our approach is something that's easy to get addicted to!
Now, all of these ideas are okay to impart some color to your water. Some do more, as we've discussed ad nauseam. And none of them will work to full advantage if your aquarium is removing them as fast as you're imparting them into the water. So, go easy on chemical filtration media like carbon. I didn't say NOT to use them...Just don't use a ton of them! Use less than what the manufacturer recommends.
What about plants?
Well, I have a theory about plants and tannins...
First off, as you know by now, you absolutely can keep plants in blackwater aquariums. We've talked about this a million times over the years. And yet, interestingly, you can't always keep "blackwater conditions" (at least, color-wise) in planted aquariums! There has been much geeky discussion on this topic.
Tannin are interesting things. Think about this:
Tannins are known to bind up heavy metals and minerals. The roots of aquatic plants prefer to take up bound-up minerals and metals...So, another theory of mine is that heavily planted tanks do actually remove some of the visual "tint" (ie; the tannins) from the water via uptake from their roots.
Make sense? Maybe?
Okay, I could go on and on all day throwing out all sorts of theories and unsubstantiated (via lab tests and rigorous studies, anyways) ideas on this topic...But I think I gave you enough here to get the party started. I encourage you to do some homework. We need to ask these questions to people who really understand the chemistry here. I think that there might be some good answers out there.
And, back to the "color thing" to close on here...
I admit, visual "tint" is probably THE single most superficial aspect of what we experience with botanical-method aquariums- but the most obvious, and likely the most impactful to the casual hobbyist or observer.
It's just as important to understand the collateral benefits of utilizing botanical materials- a subject we've discussed dozens of times here. However, in the end, it's the look of your aquarium that is what you have to experience each and every day, and if having an understanding of which materials can bring you the aesthetic experience you're after in a more effective way- well, then this is a worthwhile discussion, right?
I think that it is.
Stay curious. Stay resourceful. Stay enthusiastic. Stay observant. Stay appreciative. Stay tinted...
And Stay Wet.
The garden suggests there might be a place where we can meet Nature halfway."-Michael Pollan
It's long been suggested that an aquarium is sort of like a garden, right? And, to a certain extent it is. Of course, we can also allow our tanks to evolve on a more-or-less "random" path than the word "garden" implies...
Perhaps one of the most liberating things about our botanical-method aquariums is that there is no set "style" that you have to follow to "arrange" botanical materials in your tank.
When you look at those amazing pictures of the natural habitats we love so much, you're literally bombarded with the "imperfection" and apparent randomness that is Nature. Yet, in all of the "clutter" of an igarape flooded forest, for example, there is a quiet elegance to it. There is a sense that everything is there for a reason- and not simply because it looks good. It IS perfect. Can't we bring this sense to our aquariums?
I think we can...simply by meeting Nature halfway.
To a certain extent, it's "anything goes" in terms of adding materials to represent the wild habitats. I mean, when you think about flooded forest floors and rainforest streams, you're talking about an aggregation of material from the forest that has accumulated via wind, rain, and current. The influences on the "design" are things like how something arrives into the water, and how it gets distributed by water movement.
Nature offers no "style guide."
Rather, she offers clues, based on her processes.
I mean, sure, you could and should certainly use some aesthetic thought in the concept, but when you're trying to recreate what in Nature is a more-or-less random thing, you probably don't want to dwell too much on the concept! You don't want to over-think "random" too much, right? Rather, put your effort into selecting suitable materials with which to do the job.
For a bit more context, just think for just a second, about the stems and branches that we love so much in our aquascaping. Those of us who obsessively study images of the wild tropical habitats we love so much can't help but note that many of the bodies of water which we model our aquariums after are filled with tree branches and stems.
Since many of these habitats are rather ephemeral in nature, they are only filled up with water part of the year. The remainder of the time, they're essentially dry forest floors.
And what accumulates on dry forest floors?
Branches, stems, leaves, and other materials from trees and shrubs. When the waters return, these formerly terrestrial materials become an integral part of the (now) aquatic environment. This is a really, really important thing to think of when we aquascape or contemplate how we will use botanical materials like the aforementioned stems and branches.
They impact both function and aesthetics of an aquarium...Yes, what we call "functional aesthetics" rears its head again!
There is no real rhyme or reason as to why stuff orients itself the way it does once submerged. There are numerous random factors involved.
I mean, branches fall off the trees, a process initiated by either rain or wind, and just land "wherever." Which means that we as hobbyists would be perfectly okay just literally tossing materials in and walking away! Now, I know this is actually aquascaping heresy- Not one serious 'scaper would ever do that...right?
On the other hand, I'm not so sure why they wouldn't!
I mean, what's wrong with sort of randomly scattering stems, twigs, and branches in your aquascape? It's a near-perfect replication of what happens in Nature. Now, I realize that a glass or acrylic box of water is NOT nature, and there are things like "scale" and "ratio" and all of that shit that hardcore 'scapers will hit you over the head with...
But Nature doesn't give a fuck about some competition's "rules"- and Nature is pretty damn inspiring, right? There is a beauty in the brutal reality of randomness. I mean, sure, the position of stones in an "Iwagumi" is beautiful...but it's hardly what I'd describe as "natural."
Natural looks...well, like what you'd see in Nature.
It's pretty hardcore stuff.
And it's all part of the reason that I spend so damn much time pleading with you- my fellow fish geeks- to study, admire, and ultimately replicate natural aquatic habitats as much as you do the big aquascaping contest winners' works. In fact, if every hobbyist spent just a little time studying some of these unique natural habitats and using them as the basis of their work, I think the hobby would be radically different.
When hobbyists interpret what they see in wild aquatic habitats stats more literally, the results are almost always stunning. And contest judges are starting to take notice...
I think that there would also be hobby success on a different level with a variety of fishes that are perhaps considered elusive and challenging to keep. Success based on providing them with the conditions which they evolved to live in over the millennia, not a "forced fit" its what works for us humans.
More awareness of both the function and the aesthetics of fascinating ecological niches, such as the aforementioned flooded forests, would drive the acceptance and appreciation of Nature as it is- not as we like to "edit" and "sanitize" it.
Taking this approach is actually a "stimulus" for creativity, perhaps in ways that many aquarists have not thought of.
There are a lot of aquatic habitats in Nature which are filled with tangles of terrestrial plant roots, emergent vegetation, fallen branches, etc., which fill small bodies of water almost completely.
These types of habitats are unique; they attract a large populations of smaller fishes to the protection of their vast matrix of structures. Submerged fallen tree branches or roots of marginal terrestrial plants provide a large surface area upon which algae, biofilm, and fungal growth occurs. This, in turn, attracts higher life forms, like crustaceans and aquatic insects. Sort of the freshwater version of a reef, from a "functionality" standpoint, right?
Can't we replicate such aquatic features in the aquarium?
Of course we can!
This idea is a fantastic expression of "functional aesthetics." It's a "package" that is a bit different than the way we would normally present an aquarium. Because we as hobbyists hesitate to densely pack an aquarium like this, don't we?
Why do you think this is?
I think that we hesitate, because- quite frankly- having a large mass of tangled branches or roots and their associated leaves and detritus in the cozy confines of an aquarium tends to limit the number, size, and swimming area of fishes, right? Or, because its felt that, from an artistic design perspective, something doesn't "jibe" about it...
Sure, it does limit the amount of open space in an aquarium, which has some tradeoffs associated with it.
On the other hand, I think that there is something oddly compelling, intricate, and just beautiful about complex, spatially "full" aquatic features. Though seldom seen in aquarium work, there is a reason to replicate these systems. And when you take into account that these are actually very realistic, entirely functional representations of certain natural habitats and ecological niches, it becomes all the more interesting!
What can you expect when you execute something like this in the aquarium?
Well, for on thing, it WILL take up a fair amount of space within the tank. Of course. Depending upon the type of materials that you use (driftwood, roots. twigs, or branches), you will, of course, displace varying amounts of water.
Flow patterns within the aquarium will be affected, as will be the areas where leaves, detritus and other botanical materials settle out. You'll need to understand that the aquarium will not only appear different- it'll function differently as well. Yet, the results that you'll achieve- the more natural behaviors of your fishes, their less stressful existence- will provide benefits that you might not have even realized possible before.
This is something which we simply cannot bring up often enough. It's transformational in our aquarium thinking.
The "recruitment" of organisms (algae, biofilms, epiphytic plants, etc.) in, on, and among the matrix of wood/root structures we create, and the "integration" of the wood into other "soft components" of the aquascape- leaves and botanicals is something which occurs in Nature as well as in the aquairum.
This is an area that has been worked on by hobbyists rather infrequently over the years- mainly by biotope-lovers. However, embracing the "mental shifts" we've talked about so much here- allowing the growth of beneficial biocover, decomposition, tinted water, etc.- is, in our opinion, the "portal" to unlocking the many secrets of Nature in the aquarium.
The extraordinary amount of vibrance associated with the natural growth on wood underwater is an astounding revelation. However, our aesthetic sensibilities in the hobby have typically leaned towards a more "sterile", almost "antispetic" interpretation of Nature, eschewing algae, biofilm, etc.
However, a growing number of hobbyists worldwide have began to recognize the aesthetic and functional beauty of these natural occurances, and the realism and I think that the intricate beauty of Nature is starting to eat away at the old "sterile aquascape" mindset just a bit!
And before you naysayers scoff and assert that the emerging "botanical method" aquarium is simply an "excuse for laziness", as one detractor communicated to me not too long ago, I encourage you once again to look at Nature and see what the world underwater really looks like. There is a reason for the diversity, apparent "randomness", and success of the life forms in these bodies of water.
What is it?
It's that these materials are being utilized- by an enormous community of organisms- for shelter, food, and reproduction. Seeing the "work" of these organisms, transforming pristine" wood and crisp leaves into softening, gradually decomposing material, is evidence of the processes of life.
When you accept that seed pods, leaves, and other botanical materials are somewhat ephemeral in nature, and begin to soften, change shape, accrue biofilms and even a patina of algae- the idea of "meeting Nature halfway" makes perfect sense, doesn't it?
You're not stressing about the imperfections, the random patches of biofilm, the bits of leaves that might be present in the substrate. Sure, there may be a fine line between "sloppy" and "natural" (and for many, the idea of stuff breaking down in any fashion IS "sloppy")- but the idea of accepting this stuff as part of the overall closed ecosystem we've created is liberating.
Sure, we can't get every functional detail down- every component of a food web- every biochemical interaction...the specific materials found in a typical habitat- we interpret- but we can certainly go further, and continue to look at Nature as it is, and employ a sense of "acceptance"- and randomness-in our work.
I'm not telling you to turn your back on the modern popular aquascaping scene; to disregard or dismiss the brilliant work being done by aquascapers around the world, or to develop a sense of superiority or snobbery, and conclude that everyone who loves this stuff is a sheep...
Not at all.
I'm simply the guy who's passing along the gentle reminder from Nature that we have this great source of inspiration that really works! Rejoice in the fact that Nature offers an endless variety of beauty, abundance, and challenge- and that it's all there, free for us to interpret it as we like. Without aesthetic rules, rigid standards, and ratios. The only "rules" are those which govern the way Nature works with materials in an aquatic environment.
A botanical-method aquarium features, life, death, and everything in between.
It pulses with the cycle of life, beholden only to the rules of Nature, and perhaps, to us- the human caretakers who created it.
But mainly, to Nature.
The processes of life which occur within the microcosm we create are indifferent to our desires, our plans, or our aspirations for it. Sure, as humans, we can influence the processes which occur within the aquarium- but the ultimate outcome- the result of everything that we did and did not do- is based solely upon Nature's response.
In the botanical-style aquarium, we embrace the randomness and unusual aesthetic which submerged terrestrial materials impart to the aquatic environment. We often do our best to establish a sense of order, proportion, and design, but the reality is that Nature, in Her infinite wisdom borne of eons of existence, takes control.
It's a beautiful process. Seemingly random, yet decidedly orderly.
Think about that for a bit.
Stay curious. Stay bold. Stay creative. Stay thoughtful...
And Stay Wet.
I'm fascinated by the dietary preferences of fishes. How they've evolved over eons to consume various items found in their environments; how many fishes became "specialists" as an adaptation to the habitats in which they live.
And, as an aquarist who derives great pleasure from seeing his fishes "live off the land" and consume foods from the aquarium environment in which they reside, I really find some of the seunderlying feeding strategies fascinating. One of the more interesting examples is the consumption of wood by various species of fishes.
We read a lot about fishes which eat wood and wood-like materials.
Of course, the ones that come immediately to mind are the Loricariidae, specifically, Panaque species. Now, I admittedly am the last guy who should be authoritatively discussing the care of catfishes, having maintained maybe a couple dozen or so species during a lifetime of aquarium keeping. However, I do understand a little bit about their diets and the idea of utilizing wood- and botanical materials- in the aquarium for the purpose of supplementing our fishes' diets!
And of course, I'm equally fascinated by the world of biofilms, decomposition, microorganism growth and detritus...And this stuff plays right into that!
Now, the idea of xylophagy (the consumption and digestion of wood) is of course, a pretty cool and interesting adaptation to the environment from which these fishes come from. And as you'd suspect, the way that wood is consumed and digested by these fishes is equally cool and fascinating!
It's thought by ichthyologists that the scraping teeth and highly angled jaws of the Loricariidae are a perfect adaptation to this feeding habit of "scraping" wood. And of course, it's even argued among scientists that these fishes may or may not actually digest the wood they consume! While scientists have identified a symbiotic bacteria which is found in the gut of these fishes that helps break down wood components, it's been argued by some the the fishes don't actually digest and metabolize the wood; indeed deriving very little energy from the wood they consume!
In fact, a lab study by Donovan P. German was described in the November, 2009 Journal of Comparative Physiology, in which several species were fed wood and found to actually digest it quite poorly:
"...in laboratory feeding trials, (Pterygoplichthys cf. nigrolineatus and Hypostomus pyrineusi) lost weight when consuming wood, and passed stained wood through their digestive tracts in less than 4 hours. Furthermore, no selective retention of small particles was observed in either species in any region of the gut. Collectively, these results corroborate digestive enzyme activity profiles and gastrointestinal fermentation levels in the fishes’ GI tracts, suggesting that the wood-eating catfishes are not true xylivores such as beavers and termites, but rather, are detritivores like so many other fishes from the family Loricariidae."
Did you see that? Detritioves. Like, they're taking in wood to get other stuff out of the deal... And detritus is comprised of stuff like macrophytes, algae, and particulate organic carbon.
And this little nugget from the same study: "...The fishes consumed 2–5% of their body mass (on a wet weight basis) in wood per day, but were not thriving on it, as Pt. nigrolineatus lost 1.8 ± 0.15% of their body mass over the course of the experiment, and Pt. disjunctivus lost 8.4 ± 0.81% of their body mass."
Oh, that's weird.
Yet, anatomical studies of these fishes showed that the so-called "wood-eating catfishes" had what physiologists refer to as "body size-corrected intestinal lengths" that were 35% shorter than the detritivore species. What does this mean? Could they have perhaps had at one time- and subsequently lost- their ability to digest wood?
And to make it even weirder, check out this passage from a study by Lujan, Winemiller, and Armbruster:
"Loricariids have a dense endoskeleton and are covered with dermal plates composed primarily of calcium phosphate, giving them a high physiological demand for dietary phosphorus. Paradoxically, the rivers and streams inhabited by loricariids as well as the detritus and biofilm that most loricariids consume tend to be highly Phosporus deficient."
The same study noted that, "Loricariids as a whole are largely unable to digest lignocellulose, and instead derive most nutrients and energy from easily digestible breakdown products (e.g., disaccharides and dipeptides) that are produced during microbial degradation of submerged, decomposing wood."
I think it's yet another case of us as hobbyists drawing innocent conclusions based on anecdotal or superficial observations. I mean,"... they're munching on my wood, therefore, they must be 'eating' it!"
Now, to the point of the argument that most loricariids are primarily detritivores, consuming a matrix of biofilm, algal growth, microorganisms, and (for want of a better word) "dirt"- what does this mean to us as hobbyists? Well, for one thing, this has made them remarkably adaptable fishes in the aquarium. They will definitely rasp at wood", but according to the studies I just cited, they are not "eating" it, per se.
Now, my personal experience with Loricariidae is nothing like many of yours, and an observation I've made over the years is at best anecdotal- but interesting:
If you follow "The Tint", you know I've had a years-long love affair with Peckolotia compta aka "L134 Leopard Frog"- a beautiful little fish that is filled with charms. Well, I recall, are years back, that my first specimen seemed to have vanished into the ether following a re-configuration/rescape of my home blackwater/botanical-method aquarium. I thought somehow I either lost the fish during the re-scape, or it died and subsequently decayed without my detecting it... Pretty upsetting either way, but I couldn't find any trace of it!
For almost three months, the fish was M.I.A., just....gone.
And then one, day- there she was, poking out from the "Spider Wood" thicket that formed the basis of my newer hardscape! To say I was overjoyed was a bit of an understatement, of course! And after her re-appearance, she was out every day. She looked just as fat and happy as when I last saw her in the other 'scape...which begs the question (besides my curiosity about how she evaded detection)- What the fuck was she feeding on during this time?
Well, I suppose it's possible that some bits of frozen food (I fed frozen almost exclusively at that time) got away from my population of hungry characins and fell to the bottom...However, I'm pretty fastidious- and the other fishes (characins) were voracious mid-water-column feeders! To think that any appreciable amount got away from the hungry hoard was a bit hopeful. I believed at the time (and now am fully convinced) that it was more likely the biofilms, fungal growth, and perhaps some of the compounds from surface tissues of the "Spider Wood" I used in the hardscape that she was feeding on.
"Spiderwood" (aka Azalea root) stuff does recruit significant biological growth on it's surfaces when submerged , and curiously, in this tank, I noticed that, during the first few months, the wood seemed to never accumulate as much of this stuff as I had seen it do in past tanks which incorporated it!
I attributed this to perhaps some feeding by a population of Nanostomus eques, which have shown repeatedly in the past to feed on the biofilm or "aufwuchs" accumulating on the wood.
I'm sure that was a valid observation, but they were actively taking prepared foods as the bulk of their diet, so I have a hard time that they solely were responsible.
There was also a layer of Live Oak leaves distributed throughout the booth of the wood matrix, which, although they break down very slowly compared to other leaves we use, DO ultimately soften over time and break down over time. Since they are rather "durable", they do accumulate a lot of fungal growth and biofilms on their surfaces.
Interestingly, in this tank, I was finding little tiny amounts of very broken-down leaves, which I attributed to decomposition, but thinking back on it, looks more like the end product of "digestion" by someone!
I don't think I ever saw my L134 consuming prepared food. When I did observe her activities, she was seemingly "grazing" away at the wood surfaces and on botanicals...That's all the proof that I needed to confirm my theory that she's pretty much 100% detritivorous, and that the botanical-method aquariums she's resided in provide a sufficient amount of this material for her to consume.
To this day, I've never seen her eat prepared foods!
I have since acquired three captive-bred specimens from my friend, master breeder Sumer Tiwari, and this group has been seen to take prepared food on occasion. At the very least, adding some pellets or frozen foods seems to initial some kind of response in the fish, wether they appear to eat it or not.
So, back the the whole "xylophore thing"... After reading the studies I mentioned, I think that in the aquarium, as well as in the wild, much of what we think is actually "consumption" of the wood by the fishes is simply incidental- as in, the fishes are trying to eat the biocover and detritus on the surface tissues of the wood, and perhaps obtain some nutrition from the compounds contained in the softer portions of the wood. They apparently do a pretty good job (with their specialized mouthparts) of rasping away the surface tissues of the wood!
So, yeah- apparently, some of the wood may pass through the digestive tract of the catfishes, but it's passed without metabolizing much from it...perhaps like the way chickens consume gravel, or whatever (don't they? City boy here! WTF do I know about chickens!)...or the way some marine Centropyge angelfishes "nibble" on corals in their pursuit of algae, detritus, and biofilms.
Again, my perusal of German's scientific paper seems to support this theory:
"Catfishes supplement their wood diet with protein-rich detritus, or even some animal material to meet their nitrogen requirements. Although I did not observe animal material in the wood-eating catfish guts, Pt. disjunctivus did consume some animal material (including insects parts, molluscs, and worms), and all three species consumed detritus."
And finally, the "clincher", IMHO: "The low wood fiber assimilation efficiencies in the catfishes are highly indicative that they cannot subsist on a wood only diet."
I mean, it's just one paper, but when he's talking about isotopic tracing of materials not consistent with digestion of wood in the guts of Loricariids, I think that pretty much puts the "eats wood" thing to bed, right? His further mention that, although some cellulose and lignin (a component of wood and our beloved botanicals!) was detected in the fish's fecal material, it was likely an artifact of the analysis method as opposed to proof that the fishes derived significant nutrition from it.
So what does all of this stuff mean to us?
Well, for one thing, once again- detritus/biofilm/fungal growths = good. Don't loathe them. Love them.
Your fishes apparently do.
I think it means that, as hobbyists probably knew, theorized, and discussed for a long time- that the Loricariids consume detritus, biofilms, and prepared foods when available. This is not exactly earth-shattering or new.
However, I think understanding that our botanical-method aquariums can- and do- provide a large amount of materials from which which these and other fishes can derive significant nutrition furthers my assertion that this type of system is perfect for rearing and maintain a lot of specialized feeders.
Materials like the harder-"shelled" botanicals (ie; "Skyfruit" pods, Cariniana pods, Mokha pods, bark, etc.) tend to recruit significant fungal growths and biofilms, and accumulate detritus in and on their surfaces. And of course, as they soften, some fishes apparently rasp and "consume" some of them directly, likely passing most of it though their digestive systems as outlined in the cited study, extracting whatever nutrition is available to them as a result. This is likely the case with leaves and softer botanicals as well.
The softer materials might also be directly consumed by many fishes, although the nutrition may or may not be significant. However, the detritus, fungal, and microorganism growth as a result of their decomposition is a significant source of nutrition for many fishes and shrimps.
Detritivores (of which the amount of species in the trade is legion), have always done very well in botanical-method aquariums, and the accumulation of biofilms and microbial growth is something that we've discussed for a long time. By their very nature, the structure and decomposition of botanical materials make the "functional aesthetics" of our aquariums an important way to accommodate the natural feeding behaviors of our fishes.
So, the answer to the question (literally!), "Who has the (literal) guts for this stuff?" is quite possibly, "everyone!"
Now, while while we're on the subject of loricariids, a further scan of scientific literature revealed some interesting things about what these fishes are actually taking in when they "graze" in the wild. It's kind of eye opening, to me. One study revealed that loricariids consumed five principal items: sponges, organic detritus, bryophytes, bryozoans and sediment.
Wood is definitely part of the equation somewhere, but for the species examined in one of the studies I found (Rhinelepis aspera, Hypostomus regani, H. ternetzi, H. maragaritifer, H. microstomus, and Megalancistrus aculeatus) the gut content analysis was quite revealing:
The food spectrum of R. aspera is primarily "organic detritus and small quantities of sediment"; with few periphytic organisms. Although H. regani was found to consume large quantities of organic detritus as well, it also consumed "plant detritus, various sediment, and periphytic organisms" (i.e.; bryozoans, sponges and aquatic insect larvae). Bryozoans and sponges, huh?
Wow! Freshwater sponges...
The study indicated that bryozoans and organic detritus were the main food food of H. ternetzi, which, according to the gut contents of a number of individuals, tended to consume more sediment, rotifers, chironomids (i.e.; "Bloodworms'), gastropods and harpacticoids than the other species.
Harpactoids...you mean, like "copepods?" Stuff we as reefers feed all the time? H. margaritifer was found to ingest plant material. Other periphytic organisms such as insect larvae, and those bryozoans and sponges contributed to the diet of H. margaritifer.
And it gets more interesting still...
Sponges- I can't let that go.
Sponges were the principal food resource of H. microstomus and M. aculeatus, along with a healthy does of chironomids, various gastropods, Trichoptera (insects), and some bryozoans also consumed. Diets of these two fishes were composed of larger-sized items, with the finer organic detritus and such being less important than it was to the other species in the study.
This kind of information is tantalizing. It's compelling.
And what really gets me going is learning that some of our favorite, most beloved fishes are consuming large quantities of materials that I doubt any freshwater aquarist adds to his/her arsenal of foodstuffs. We're really good at feeding our catfishes baby vegetables and stuff, while typically overlooking many species' surprisingly high dietary dependency on items like insects, bryozoans, harpactoid copepods, and interestingly...sponges!
While we kind of always knew that these fishes ingested wood and "stuff", it's interesting to see what they're actually eating in the wild...especially the "stuff"- and configuring our aquariums and the supplemental and primary feeding opportunities available to the fishes accordingly.
We have some interesting, yet perhaps overlooked possibilities to provide some of these items.
In fact, there are a number of marine aquarium-purposed foods (typically targeted at certain marine angelfishes, many of which consume significant quantities of sponge) which contain sponges in their formulation. One of my favorite is Ocean Nutrition's "Angel Formula." Granted, these foods contain stuff like mussels, and other marine foods, and the sponges included are marine sponges, but I can't help but wonder if these are that morphologically or nutritionally different/palatable to the fishes than a freshwater/tree sponge would be?
Could the next great frozen Loricarid food include sponges? And we DO have harpactoid copepods available live, and in a variety of other formats intended for marine fishes and corals...Interestingly, I remember that the big "knock" by us reefers, for a long time, about some of these copepods was that they were "freshwater" varieties, and therefore didn't have the "correct" nutritional profile for marine organisms.
Hmm. We're talking about freshwater fishes here, right? Yeah.
So, like, why the hell haven't we been feeding these foods to our freshwater fishes all of these years?
Try some of these foods with your loricariids..and other fishes as well. What's to lose?
Oh, I can hear the objections:
Is it?. Online ordering is really cool. It might just catch on.
"Too much work!"
Really? C'mon. Ever cultured Grindal Worms or wingless fruit flies? THAT is "too much work" by definition.
"This is ridiculous; No need to experiment with these wacky foods. We're doing just fine now with Zucchini and stuff! Stupid."
Urghhhhh. "If man was meant to fly, he'd have wings..."
To not experiment is stupid, IMHO.
Don't be stupid. And I mean that in the kindest way possible. Don't just accept "what works" as "the way."
Push forward. Experiment. Fail quickly, or move forward rapidly with success. Play a hunch or two. Try something different. This is how advances in the hobby are made. This is how breakthroughs happen.
You gotta try.
Stay studious. Stay curious. Stay observant. Stay engaged. Stay resourceful...
And Stay Wet.
One of the things that we find ourselves doing in the aquarium hobby is using " a little of this and that" in our tanks, because-well- because we seem to be fixated on lots of variety of "stuff" in our tanks, right?
I mean, there is nothing wrong with using a diversity of materials in our aquariums to express our creativity, and I DO own a company which sells a significant variety of natural aquascaping materials...However, I think it's important to consider exactly what it is we're trying to accomplish in our tanks when we select and employ botanical materials in our aquariums.
As we've discussed a lot around here, the idea of using natural materials, like wood, leaves, seed pods, and roots is a faithful representation of many of the wild habitats we obsess over. And more important, it's a functional methodology of fostering natural processes and a healthy ecology in our tanks.
Are you simply trying to add some aquascaping interest to your tank? Are you interested in manipulating the aquarium water chemistry? Perhaps you're attempting to replicate a very specific ecological niche? Setting up a system for breeding fishes or rearing their fry?
There are many, many applications for botanicals in aquariums. A wide range of things you can do with them, and an even wider range of botanicals to do the job. And the most important "job" for botanicals in our aquariums, IMHO, is to foster the ecology of the aquarium...The so-called "microbiome."
And the important thing to know in this context is that you don't have to use 25 different botanicals and leaves in your aquarium to achieve this ecology within your tank. The reality is that, organisms like fungal growth, bacteria, Paramecium, and other microfauna are typically not tied to a specific leaf or seed pod, so not having a huge variety doesn't mean that you won't be able to achieve a significant microbiome within your tank.
So from a "biodiversity" or ecological standpoint, there is no reason why you would need a huge variety of botanicals in a given aquarium. It really boils down to aesthetics. Or, if you're trying to be more "biotopically accurate"- it depends upon the variety of materials that you'd expect to find in the habitat you're interested in replicating.
For example, a flooded forest might have a lot more ( in both density and variety) leaves and seed pods than say, a fast-flowing river, stream, or a small oxbow lake might have. Other locales might simply have a lot of a few materials, like branches and leaves, but minimal amounts of seed pods and other materials.
Maybe you're not trying to replicate any specific habitat at all. Perhaps it's simply a creative expression with botanicals. That's fine. You can use as many or as little as you want...and you still get the "functional" aspects if you don't "edit" them!
How your botanical-style aquarium looks and (to a lesser extent, functions) is dependent upon these types of characteristics. Yet, it's really a matter of what works best for the aquarium that you are trying to create. The power of restraint is a very important factor when playing with botanicals!
Now again, with all of the cool botanical materials available to hobbyists here and elsewhere, it's certainly fun to use a large variety of different materials in your tank! I personally have always been of the opinion that too much variety in a given tank is sort of distracting and just somehow doesn't always look good. I mean, it certainly can..it just doesn't always! Somehow, using a little less variety in a given tank seems to just look a bit better, IMHO.
However, as we've mentioned already, if you're replicating a specific habitat that might have a wide variety of materials in a given small locale, it makes sense, right?
And there is the benefit of a field of botanicals not only cultivating microbial and fungal food sources for fishes, there is the direct consumption of the botanicals (or their constituent materials) by fishes.
Yes, direct consumption of botanicals by fishes is something that we haven't talked all that much about over the years here.
It's long been known that many species of fishes, particularly Panaque/Panaqolus and some Hypostomus/Cochliodon love botanical stuff. These species are equipped with teeth specifically "designed" to gouge wood. And there's probably another odd one or two that consume it as well. Now, you should be aware that wood "eaters" don't consume the wood per se, they consume it as a "by-product" of their overall feeding strategy.
(The "business end" of Panaque nigrolineatus by Neale Monks, used under CC BY-SA 3.0)
In fact, some recent scientific studies have corroborated digestive enzyme activity profiles and gastrointestinal fermentation levels in the fishes’ GI tracts, suggesting that the "wood-eating catfishes" are not true xylivores, such as beavers and termites, but rather, are detritivores like so many other fishes from the family Loricariidae.
In fact, the conclusion of one study indicated that "..the fishes’ whole digestive strategy ranging from intake, to passage rate, digestive enzyme activities, gastrointestinal fermentation, and decreasing surface area in the distal intestine suggests that these fishes are geared for the digestion and assimilation of soluble components of their detrital diet.
However, the wood-eating catfishes do take macroscopic detritus (i.e., woody debris) and reduce it to <1 mm in diameter, which likely has significant consequences for carbon cycling in their environment. Given that much of the Amazonian basin is unstudied, and much of it is under threat of deforestation (leading to more wood in waterways), the wood-eating catfishes may play a crucial role in the dynamics of the Amazonian ecosystem, and certainly in the reduction of coarse woody debris."
(German DP. Inside the guts of wood-eating catfishes: can they digest wood? Journal of Comparative Physiology B, Biochemical, Systemic, and Environmental Physiology. 2009;179(8):1011-1023. doi:10.1007/s00360-009-0381-1.)
And it has some implication for how we keep these fishes in our botanical-style aquariums, right? I mean, we have no shortage of pics of your Plecos tearing into various botanicals, ranging from leaves to seed pods, like the Calotropis pods, Cariniana pods, etc. So, based on the study above, it would suggest that at least part of the pods do form a part of the diet of these fishes, and in the process of consuming them, the fishes are helping enrich the aquarium habitat.
Now, the botanicals themselves may not be "the whole meal" for many fishes, but the biofilms, algal threads, and other biocover which grow on them do provide foraging for many fishes. A number of us have noticed a wide-ranging variety of fishes, from Barbs to characin to cichlids, feeding actively on the materials on the materials which are "recruited" by submerged botanicals.
This type of activity has led me to postulate that the use of botanicals can perform a definite "feeding support function" for a wide variety of fishes. So, I suppose, one advantage of a variety of botanical materials in one tank is that it increases your chances of having something palatable to someone in the tank!
If you've followed us for any length of time, you're well aware that we are not just pushing you to play with natural, botanical-style aquariums only for the pretty aesthetics. I mean, yeah, they look awesome, but there is so much more to it than that. We are almost as obsessed with the function of these aquariums and the wild habitats which they attempt to represent!
Understanding why you're choosing to throw botanicals in your aquarium is as important as it is to understand how to employ them. Regardless of how you employ the botanicals, I cannot stress enough the need to go SLOWLY. There is no need to rush and dump everything in at one time, or in huge quantities. Particularly in an established aquarium, where your animals are used to a certain stable range of parameters...It goes without saying that if your introducing materials which can influence water chemistry and quality, you will need to go slow and exercise common sense.
And, since botanicals are actively "breaking down" in your aquarium over their "service lifetimes", it's important to employ good husbandry techniques (i.e.; monitoring of water quality, water changes, regular filter media changes, etc.). Just remind yourself that aquatic botanicals create a "dynamic" environment, and you'll enjoy using them that much more!
Apart from, "What pods should I use for a _____________ style setup?" the most common question we receive is ""Do I leave them in or let them break down in my tank?"
And of course, our simple, likely unsatisfying answer is..."It's your call!"
It's as much about your aesthetic preferences as it is long-term ecological stability of the aquarium. It's a decision that each of us makes based on our tastes, management "style", and how much of a "mental shift" we've made o except the transient nature of a botanical-style aquarium and its function. There really is no "right" or "wrong" answer here. It's all about how much you enjoy what happens naturally versus what you choose to control in your tank.
I tend to favor Nature. Every time. It's not even close.
But that's just me.
And of course, we can't ever lose sight of the fact that we're creating and adding to a closed aquatic ecosystem, and that our actions in how we manage our tanks must map to our ambitions, tastes, and the "regulations" that Nature imposes upon us.
Yes, anything that you add into your aquarium that begins to break down is bioload.
Everything that imparts proteins, lignins, tannins, organics, etc. into the water is something that you need to consider. However, it's always been my personal experience and opinion that, in an otherwise well-maintained aquarium, with regular attention to husbandry, stocking, and maintenance, the"burden" of botanicals on your water quality is surprisingly insignificant.
Even in test systems which I intentionally "neglected" by conducting very sporadic water exchanges, once I hit my preferred "population" of botanicals (by building them up gradually), I have never noticed significant phosphate or nitrate increases that could be attributed to their presence.
So, once and for all- is adding a bunch of botanicals to your aquarium "dangerous?"
I mean, it could be, in some instances. Like, adding large quantities of fresh botanicals to an established, stable tank all at once is a recipe for problems. But, this is "Aquarium Keeping 101", right? Like, what would you expect that would happen? Why would you even do that?
It's about common sense.
The reality is, adding botanicals to your tank and using them, replacing them regularly, etc, is no more "dangerous" than anything else we do as aquarists. You simply need to go slowly, apply common sense, follow our prep instructions, and observe your tank carefully.
Look, stuff can still occasionally go wrong, even when you follow instructions and employ common sense. Never lose sight of the fact that aquariums are closed natural ecosystems, and changing the delicate ecological balance within them always risks disrupting established biological processes- and that can have consequences for your fishes.
But, you already KNOW that
It's the reality of Nature, and a reminder that, although we can control some things, Mother Nature calls the shots...
So, the power of "chilling out"- the ability to exercise restraint; to not go crazy adding a ton of stuff all at once- is a huge and very, very important skill for all who play with botanicals to acquire.
I'll bet that you already have.
Stay creative. Stay curious. Stay excited. Stay restrained...
And Stay Wet.
One of the things that drives most hobbyists crazy is when "stuff" gets blown around, covered or moved about in the aquarium. It can be because of strong current, the activity of fishes, or simply overgrown by plants. I understand the annoyance that many hobbyists feel; I recall this same aggravating feeling in many reef tanks where I had high flow and sand on the bottom- almost always a combination for annoyance!
I mean, I get it. We have what feel is a carefully thought-out aquascape, looking exactly how we expected it would after setup. Yet, despite our ideas and thoughts, stuff moves around in the aquarium. It's something we can either accept, or modify in our aquariums, depending upon our preferences.
Yet, movement and "covering" of various materials by sediments, biofilms, etc., which accumulate on the substrate in natural habitats are everyday occurrences, and they help forge a very dynamic ecosystem. And they are constantly creating new opportunities for the fishes which reside in them to exploit.
When you think about how materials "get around" in the wild aquatic habitats, there are a few factors which influence both the accumulation and distribution of them. In many topical streams, the water depth and intensity of the flow changes during periods of rain and runoff, creating significant re-distribution of the materials which accumulate on the bottom, such as leaves, branches, seed pods, and the like.
Larger, more "hefty" materials, such as branches, submerged logs, etc., will tend to move less frequently, and in many instances, they'll remain stationary, providing a physical diversion for water as substrate materials accumulate around them.
A "dam", of sorts, if you will.
And this creates known structures within streams in areas like Amazonia, which are known to have existed for many years. Semi-permanent aquatic features within the streams, which influence not only the physical and chemical environment, but the very habits and abundance of the fishes which reside there.
Most of the small stuff, like leaves, tend to move around quite a bit... One might say that the "material changes" created by this movement of materials can have significant implications for fishes. As we've talked about before, they follow the food, often existing in, and subsisting off of what they can find in these areas.
New accumulations of leaves, detritus, and other materials benefit the entire ecosystem.
In the case of our aquariums, this "redistribution" of material can create interesting opportunities to not only switch up the aesthetics of our tanks, but to provide new and unique little physical areas for many of the fishes we keep.
And yeah, the creation of new feeding opportunities for life forms at all levels is a positive which simply cannot be overstated! As hobbyists, we tend to lament changes to the aquascape of our tanks caused by things outside of our control, and consider them to be a huge inconvenience, when in reality, they're not only facsimile of very natural dynamic processes-they are fundamental to their evolution.
The benthic microfauna which our fishes tend to feed on also are affected by this phenomenon, and as mentioned above, the fishes tend to "follow the food", making this a case of the fishes adapting to a changing environment. And perhaps...maybe...the idea of fishes sort of having to constantly adjust to a changing physical environment could be some sort of "trigger", hidden deep in their genetic code, that perhaps stimulates overall health, immunity or spawning?
Something in their "programing" that says, "You're at home..." Perhaps something which triggers specific adaptive behaviors?
I find this possibility fascinating, because we can learn more about our fishes' behaviors, and create really interesting habitats for them simply by adding botanicals to our aquariums and allowing them to "do their own thing"- to break apart as they decompose, move about as we change water or conduct maintenance activities, or add new pieces from time to time.
Again, just like Nature.
We just need to "get over ourselves" on this aesthetic thing!
Another mental shift? Yeah, it is. An easy one, but one that we need make, really.
Like any environment, botanical/ leaf litter beds have their own "rhythm", fostering substantial communities of fishes. The dynamic behind this biotope can best be summarized in this interesting excerpt from an academic paper on blackwater leaf-litter communities by biologist Peter Alan Henderson, that is useful for those of us attempting to replicate these communities in our aquaria:
"..life within the litter is not a crowded, chaotic scramble for space and food. Each species occupies a sub-region defined by physical variables such as flow and oxygen content, water depth, litter depth and particle size…
...this subtle subdivision of space is the key to understanding the maintenance of diversity. While subdivision of time is also evident with, for example, gymnotids hunting by night and cichlids hunting by day, this is only possible when each species has its space within which to hide.”
In other words, different species inhabit different sections of the leaf litter beds. As aquarists, we should consider this when creating and stocking our botanical-style aquariums.
It just makes sense, right?
So, when you're attempting to replicate such an environment, consider how the fishes would utilize each of the materials you're working with. For example, leaf litter areas would be an idea shelter for many juvenile fishes, catfishes, and even young cichlids to shelter among.
Submerged branches, larger seed pods and other botanicals provide territory and areas where fishes can forage for macrophytes (algal growths which occur on the surfaces of these materials). Fish selection can be influenced as much by the materials you're using to 'scape the tank as anything else, when you think about it!
And it's not just fishes, of course. It's a multitude of life forms.
There are numerous life forms which are found on ad among these materials as well, such as fungal growths, bacterial biofilms, etc. which we likely never really consider, yet are found in abundance in nature and in the aquarium, and perform vital roles in the function of the aquatic habitat.
Perhaps most fascinating and rarely discussed in the hobby, are the unique freshwater sponges, from the genus Spongilla. Yes, you heard. Freshwater sponges! These interesting life forms attach themselves to rocks and logs and filter the water for various small aquatic organisms, like bacteria, protozoa, and other minute aquatic life forms. Some are truly incredible looking organisms!
(Spongilla lacustris Image by Kirt Onthank. Used under CC-BY SA 3.0)
Unlike the better-known marine sponges, freshwater sponges are subjected to the more variable environment of rivers and streams, and have adapted a strategy of survival. When conditions deteriorate, the organisms create "buds", known as "gemmules", which are an asexually reproduced mass of cells capable of developing into a new sponge! The Gemmules remain dormant until environmental conditions permit them to develop once again!
To my knowledge, these organisms have never been intentionally collected for aquariums, and I suspect they are a little tricky to transport (despite their adaptability), just ike their marine cousins are. One species, Metania reticulata, is extremely common in the Brazilian Amazon. They are found on rocks, submerged branches, and even tree trunks when these areas are submerged, and remain in a dormant phase in the aforementioned gemmules during periods of desiccation!
Now, I'm not suggesting that we go and collect freshwater sponges for aquarium use, but I am curious if they occur as "hitchhikers" on driftwood, rocks or other materials which end up in our aquariums. When you think about how important sponges are as natural "filters", one can only wonder how they might perform this beneficial role in the aquarium as well!
We've encountered them in reef tanks for many years...I wonder if they could ultimately find their way into our botanical-style aquariums as well? Perhaps they already have. Have any of you encountered one before in your tanks?
The big takeaway from all of this: A botanical bed in our aquariums and in Nature is a physical structure, ephemeral though it may be- which functions just like an aggregation of branches, or a reef, rock piles, or other features would in the wild benthic environment, although perhaps even "looser" and more dynamic.
Stuff gets redistributed, covered, and often breaks down over time. Exactly like what happens in Nature.
Think about the possibilities which are out there, under every leaf. Every sunken branch. Every root. Every rock.
It's all brought about by the dynamic process of movement.
Perhaps instead of looking at the movement of stuff in our tanks as an annoyance, we might enjoy it a lot more if we look at it as an opportunity! An opportunity to learn more about the behaviors and life styles of our fishes and their ever-changing environment.
Stay observant. Stay creative. Stay excited. Stay open-minded...
And Stay Wet.
So, you have this idea for an aquarium.
You kind of see it in your head...you've assembled the materials, got it sort of together.
You add water.
Then, you walk in the room one day, look at it and- you just HATE it.
Like, you're done with it. Like, no re-hab on the design. No "tweaking" of the wood or whatever...You're just over the fucking thing. Ever felt that?
What do you do?
Well, I had this idea for a nano tank a while back. It seemed good in my head...I had it up for a nanosecond.
Even memorialized it with some Instagram Stories posts. Doing that is almost always the sort of thing that forces me to move on something...I mean, if you lay down a public "marker", you've got to go, right?
I thought that the tank would be a sort of "blank canvas" for an idea I had...I liked the idea, in principle.
But I didn't see a way forward with this one. I even took the extraordinary step of removing one element of the tank (the wood) altogether, in the hope of perhaps pivoting and just doing my "leaf only scape V3.0"- but I wasn't feeling it.
A stillborn idea. A tank not capable of evolving to anything that interested me at this time.
So...I let it go.
Yeah, made away with it. Shut it down. Terminated it...
Whatever you want to call it.
That's really a kind of extraordinary step for me. I mean, I'm sort of the eternal optimist. I try to make almost everything work if I can...
I mean, some of my favorite tanks evolved out of this mindset of sticking with something...We'll come back to that in bit.
Not this time, however.
I killed it.
Now, in the hours after the aborted aquarium move, I was actually able to gain some clarity about why I did it.
What made me do it?
I almost always do a sort of "post mortem" analysis when I abort on an idea, and this time was no different. It was pretty obvious to me...the "writing was on the wall" with this one!
I think it centered around two things that I simply can't handle in aquariums anymore.
1) I absolutely can't stand aquariums which don't have some sort of background- be it opaque window tint, photo paper, or paint. This tank had no background. You could see the window behind it, and the trees outside on the street, and...yeah.
2) I disdain seeing filters or other equipment in my aquariums. Like, I hate it more than you can ever even imagine. With really few exceptions, I simply hate seeing filters and stuff. It's only in recent years that I've been able to tolerate seeing filter returns in my all-in-one tanks...and just barely. Now, this nano had a little hang-on-the-back outside power filter...Which I not only saw from the top, but from behind...because-you got it- I didn't have a goddam background on the tank, yes.
I mean, am I that much of a primadonna that I can't handle that? I mean, maybe, but I like to think of it as a situation where I have simply developed an aesthetic sense that just can't tolerate some stuff anymore. I have good ideas, and then I get to equipment...and it sort of "stifles" them a bit.
This is weird.
Okay, yeah, maybe I am prima donna.
What could I have done to salvage this tank? Add a background?
Use a canister filter and glassware, you say?
Oh, sure. That's easy, right? I mean, all you see in the tank are these elegant curves of "lily pipes" and intakes...Maybe a surface skimmer...You just take 'em out and bleach 'em every once in a while and they stay nice and clean, and..
Okay, yeah. Great. On paper, anyways.
IMHO, glassware isn't the "organic art" that everyone seems to place on some lofty pedestal in the hobby. It reminds me of high school chemistry lab (which I think I got a C minus in, so some residual trauma there, no doubt). You think it's beautiful...I think it's simply dreadful.
It's another piece of equipment, which you see on the outside of the tank, too, with its "umbilical" of return lines shooting up along the sides. Now sure, I know these were developed to make an obvious, visible necessity (filter returns) more elegant and beautiful...However, to me, they're just that- obvious, visible, distracting...and ugly.
Hell, I've even made crazy efforts to hide the canister filters beneath my tanks before, when I couldn't hide them within the tank. It's like, I had to do something!
I know, I'm being waaaaay too stupid about this.
Because, really, with a lot of my reef aquarium work, and for that matter, some of my fave botanical-style tanks, you can see some of this stuff. When you see my next reef tank, you might see couple of submersible pumps in the tank , low and deep behind the rock work.
For some reason, it doesn't completely fry my brain in every single situation. I suppose it's a hypocritical thing, but man, sometimes it freaks me out and sometimes I can give it a pass.
Like, why do some tanks get a pass, and others just freak me out with this stuff.
I think, maybe, it's about the "concept"of the tank. Or the context. Like, some of my fave ever tanks, like my leaf-litter-only tanks, typically will have some equipment evident, because they are essentially a "zero-releaf" aquascape, with nothing that you can hide this stuff behind, like wood or rocks, or whatever. It's as "honest" as it gets. If you want to filter and heat the tank, you only have few options.
It never bothered me all that much in those types of tanks.
Yet, in other tanks? Just fugettaboutit!
Yeah, it MUST be about the concept of the tank. Not only will I forgive the visible equipment, sometimes I'll forgive myself the entire poor execution, too. Because, when I look back at some of the stuff I've done, that was definitely the mindset. Like, I was just happy to sort of pull it off, despite how crappy it looked, as this little gem from 2004 graphically illustrates:
Now that I look back on it, there were actually tons of times when I just let a tank evolve, unmolested and unhurried, because something spoke to me...no matter how weird or seemingly dumb the concept may have initially appeared. There was something about it that I believed in...
And occasionally, I'll try something, tear it down, and just regret it. Like, I'll realize, too late, that there was something I liked about the idea, and that I should have kept at it; let it do it's thing.
Like, what IF I kept it in play for little longer?
I mean, could it have evolved into something cool?
I recall a particular experiment I did with Spider Wood, which I let go very early in the game. The arrangement was almost a "reef like" concept...It didn't look right at the time, so I killed it way too early.
Like, a few tweaks to the wood stack, a buildup of substrate in the back of it, a buildup of some leaves and maybe some plants in the back, and it could have been a respectable recreation of the banks of some of the forest floor streams that I've seen in South America.
Yeah, I'd love to try that one again.
Then there were others which I had great faith in right from the start. Even though they looked a bit weird initially, I knew that they'd evolve into something special if I let them be.
Some just hit the right note, despite a possibly shaky start. Just knew that the idea was so special, that given the space and time, they'd eventually hit the right notes...And they did.
And, then, there were those ideas which, despite their unconventional appearance, were iconic to me, because they represented the culmination of although experiment; a transformation from research to idea to reality. Stuff which created a real transformation in the way I look at aquariums. The "Urban Igapo" style aquairums that many of us execute now, arose from just such an idea.
Sometimes, you just know it. You just feel that letting go of your preconceptions, doubts, and fears, rather than letting go of the tank-is just the right move.
Regardless of the idea, or the appearance of your tank, if there is any way to salvage what you feel is a great idea- even if it means just waiting it out for awhile- do it.
You just never know if that one "not so good"idea will turn out to be the one that changes everything for you, and inspires others in the process. Your "fail" might be the unlock- the key- for someone else who was about give up, and then suddenly saw something in your work, and created a tank based on your "failed" concept- executed on an idea-which truly touched others in ways you might not have even thought of.
So, yeah- let go...in the right way.
Stay bold. Stay patient. Stay creative. Stay optimistic. Stay enthusiastic. Stay persistent...
And Stay Wet.
As you know, we've spent the better part of the past 6 years talking about every aspect of the botanical-style aquarium that we can think of. We've talked about techniques, approaches, ideas, etc. And we've spent a lot of time sharing information about wild aquatic habitats that we might be interested in replicating in both form and function.
However, I think we haven't spent as much time as we should talking about how botanicals "behave" in wild aquatic habitats. Much of this stuff has implications for those of us who are interested in replicating these habitats in our aquariums. So, let's dive in a bit more on this topic today!
Among the trees of the flooded forests, after the fruits mature (which occurs at high water levels), seeds will fall into the water and may float on the surface or be submerged for a number of weeks. Ecologists believe that the seed production of the trees coincides with the flood pulses, which facilitates their dispersal by water movement, and by the actions of fish.
Interestingly, scientists postulate that these floating or sinking seeds, which germinate and establish seedlings after the flood waters recede, do very well, sprouting and establishing themselves quickly, and are not severely affected by waterlogging in most species.
So, within their cycle of life, the trees take advantage of the water as part of their ecological adaptation. Trees in these areas have developed specialized morphologies, such as advantageous roots, butress systems and stilt roots.
In a lot of wild aquatic habitats where leaf litter and other allochthonous materials accumulate, there are a number of factors which control the density, size, and type of materials which are deposited in streams and such. The flow rate of the water within these habitats determines a lot of things, such as the size of the leaves and other botanical materials and where in the stream they are deposited.
I often wonder how much the fallen leaves and seed pods impact the water chemistry in a given stream, pond, or section of an Amazonian flooded forest. I know that studies have been done in which ecologists have measured dissolved oxygen and conductivity, as well as pH. However, those readings only give us so much information.
We hear a lot of discussion about blackwater habitats among hobbyists, and the implications for our aquariums. And part of the game here is understanding what it is that makes this a blackwater river system to begin with. We often hear that blackwater is "low in nutrients."
What exactly does this mean?
One study concluded that the Rio Negro is a blackwater river in large part because the very low nutrient concentrations of the soils that drain into it have arisen as a result of "several cycles of weathering, erosion, and sedimentation." In other words, there's not a whole lot of minerals and nutrients left in the soils to dissolve into the water to any meaningful extent!
Black-waters, drain from older rocks in areas like the Negro river, result from dissolved fulvic and humic substances, present small amounts of suspended sediment, lower pH (4.0 to 6.0) and dissolved elements. Yes, highly leached tropical environments where most of the soluble elements are quickly removed by heavy rainfall.
Perhaps...another reason (besides the previously cited limitation of light penetration) why aquatic plants are rather scare in these waters? It would appear that the bulk of the nutrients found in these blackwaters are likely dissolved into the aquatic environment by decomposing botanical materials, such as leaves, branches, etc.
Why does that sound familiar?
Besides the color, of course, the defining characteristics of blackwater rivers are pH values in the range of 4-5, low electrical conductivity, and minimal mineral content. Dissolved minerals, such as Ca, Mg, K, and Na are negligible. And with these low amounts of dissolved minerals come unique challenges for the animals who reside in these systems.
How do fishes survive and thrive in these rather extreme habitats?
It's long been known that fishes are well adapted to their natural habitats, particularly the more extreme ones. And this was borne out in a recent study of the Cardinal Tetra. Lab results suggest that humic substances protect cardinal tetras in the soft, acidic water in which they resides by preventing excessive sodium loss and stimulating calcium uptake to ensure proper homeostasis.
This is pretty extraordinary, as the humic substances found in the water actually enable the fishes to survive in this highly acidic water which is devoid of much mineral content typically needed for fishes to survive!
And of course, botanicals, leaves, and wood typically have an abundance of these humic substances, right? They are useful for more than just an interesting and unique aesthetic effect! There is a lot of room for research about influencing the overall environment in our aquariums here! I think we've barely scratched the surface of the potential for utilizing botanicals in our aquariums.
This is another one of those foundational aspects of the natural style of aquarium that we espouse. The understanding that processes like decomposition and physical transformation of the materials that we utilize our tanks are normal, expected, and beautiful things requires us to make mental shifts.
Botanical materials don't have nearly as much impact on the water parameters (other than say, conductivity and dissolved oxygen) as the soils do. These waters have high concentrations of humic and fulvic acids derived from sandy "hydromorphic podsols" prevalent in the region. However, these allochthonous materials have huge impact on the ecology of these systems!
Leaf litter, as one might suspect, is of huge importance in these ecosystems. Especially in smaller tributaries. In one study which I came across, it was concluded that, "The smaller the stream, the more dependent the biota is on leaf litter habitats and allocthonous energy derived directly or indirectly from the forest." (Kemenes and Forsberg)
From the same study, it was concluded that the substrate of the aquatic habitat had significant influence on the feeding habits of the fishes which resided in them:
"The biomass of allocthonous insectivore increased in channels with a higher percentage of sandy bottom substrate. Detritivorous insectivore biomass, in contrast, increased significantly in channels with a higher percentage of leaf substrate. General insectivores tended to increase in streams with higher proportions of leafy substrate, too.
Whats the implication for us as hobbyists? Well, for one thing, we can set up the benthic environment in our tanks to represent the appropriate environment for the fishes which we want to keep in them. Simple as that!
t's as much about function as anything else. And, about pushing into some new directions. The unorthodox aesthetics of these unusual aquariums we play with just happen to be an interesting "by-product" of theirfunction.
I personally think that almost every botanical-style aquarium can benefit from the presence of leaves. As we've discussed numerous times, leaves are the "operating system" of many natural habitats (ecology-wise), and perform a similar role in the aquarium.
The presence of botanical materials such as leaves in these aquatic habitats is fundamental. Leaves and other botanicals are extremely pervasive in almost every type of aquatic habitat.
In the tropical species of trees, the leaf drop is important to the surrounding environment. The nutrients are typically bound up in the leaves, so a regular release of leaves by the trees helps replenish the minerals and nutrients which are typically depleted from eons of leaching into the surrounding forests.
Now, interestingly enough, most tropical forest trees are classified as "evergreens", and don't have a specific seasonal leaf drop like the "deciduous" trees than many of us are more familiar with do...Rather, they replace their leaves gradually throughout the year as the leaves age and subsequently fall off the trees.
The implication here?
There is a more-or-less continuous "supply" of leaves falling off into the jungles and waterways in these habitats, which is why you'll see leaves at varying stages of decomposition in tropical streams. It's also why leaf litter banks may be almost "permanent" structures within some of these bodies of water!
Our botanical-style aquariums are not "set-and-forget" systems, and require basic maintenance (water exchanges, regular water testing, filter media replacement/cleaning), like any other aquarium. They do have one unique "requirement" as part of their ongoing maintenance which other types of aquariums seem to nothave: The "topping off" of botanicals as they break down.
The "topping off" of botanicals in your tank accomplishes a number of things: first, it creates a certain degree of environmental continuity- keeping things consistent from a "botanical capacity" standpoint. Over time, you have the opportunity to establish a "baseline" of water parameters, knowing how many of what to add to keep things more-or-less consistent, which could make the regular "topping off" of botanicals a bit more of a "science" in addition to an "art."
In addition, it keeps a consistent aesthetic "vibe" in your aquarium. Consistent, in that you can keep the sort of "look" you have, while making subtle- or even less-than-subtle "enhancements" as desired.
And, of course, "topping off" botanicals helps keeps you more intimately "in touch" with your aquarium, much in the same way a planted tank enthusiast would by trimming plants, or a reefer while making frags. When you're actively involved in the "operation" of your aquarium, you simply notice more. You can also learn more; appreciate the subtle, yet obvious changes which arise on an almost daily basis in our botanical-style aquariums.
I dare say that one of the things I enjoy doing most with my blackwater, botanical-style aquariums (besides just observing them, of course) is to "top off" the botanical supply from time to time. I feel that it not only gives me a sense of "actively participating" in the aquarium- it provides a sense that you're doing something nature has done for eons; something very "primal" and essential. Even the prep process is engaging.
Think about the materials which accumulate in natural aquatic habitats, and how they actually end up in them, and it makes you think about this in a very different context. A more "holistic" context that can make your experience that much more rewarding. Botanicals should be viewed as "consumables" in our hobby- much like activated carbon, filter pads, etc.- they simply don't last indefinitely.
Many seed pods and similar botanicals contain a substance known as lignin. Lignin is defined as a group of organic polymers which are essentially the structural materials which support the tissues of vascular plants. They are common in bark, wood, and yeah- seed pods, providing protection from rotting and structural rigidity.
In other words, they make seed pods kinda tough.
Yet, not permanent.
That being said, they are typically broken down by fungi and bacteria in aquatic environments. Inputs of terrestrial materials like leaf litter and seed pods into aquatic habitats can leach dissolved organic carbon (DOC), rich in lignin and cellulose. Factors like light intensity, mineral hardness, and the composition of the aforementioned bacterial /fungal community all affect the degree to which this material is broken down into its constituent parts in this environment.
Hmm...something we've kind of known for a while, right?
So, lignin is a major component of the "stuff" that's leached into our aquatic environments, along with that other big "player"- tannin.
Tannins, according to chemists, are a group of "astringent biomolecules" that bind to and precipitate proteins and other organic compounds. They're in almost every plant around, and are thought to play a role in protecting the plants from predation and potentially aid in their growth. As you might imagine, they are super-abundant in...leaves. In fact, it's thought that tannins comprise as much as 50% of the dry weight of leaves!
And of course, tannins in leaves, wood, soils, and plant materials tend to be highly water soluble, creating our beloved blackwater as they decompose. As the tannins leach into the water, they create that transparent, yet darkly-stained water we love so much!
In simplified terms, blackwater tends to occur when the rate of "carbon fixation" (photosynthesis) and its partial decay to soluble organic acids exceeds its rate of complete decay to carbon dioxide (oxidation).
Chew on that for a bit...Try to really wrap your head around it...
And sometimes, the research you do on these topics can unlock some interesting tangential information which can be applied to our work in aquairums...
Interesting tidbit of information from science: For those of you weirdos who like using wood, leaves and such in your aquariums, but hate the brown water (yeah, there are a few of you)- you can add baking soda to the water that you soak your wood and such in to accelerate the leaching process, as more alkaline solutions tend to draw out tannic acid from wood than pH neutral or acidic water does. Or you can simply keep using your 8.4 pH tap water!
"ARMCHAIR SPECULATION": This might be a good answer to why some people can't get the super dark tint they want for the long term...If you have more alkaline water, those tannins are more quickly pulled out. So you might get an initial burst, but the color won't last all that long...
I think just having a bit more than a superficial understanding of the way botanicals and other materials interact with the aquatic environment, and how we can embrace and replicate these systems in our own aquariums is really important to the hobby. The real message here is to not be afraid of learning about seemingly complex chemical and biological nuances of blackwater systems, and to apply some of this knowledge to our aquatic practice.
It can seem a bit intimidating at first, perhaps even a bit contrarian to "conventional aquarium practice", but if you force yourself beyond just the basic hobby-oriented material out there on these topics (hint once again: There aren't many!), there is literally a whole world of stuff you can learn about!
It starts by simply looking at Nature as an overall inspiration...
Wondering why the aquatic habitats we're looking at appear the way they do, and what processes create them. And rather than editing out the "undesirable" (by mainstream aquarium hobby standards) elements, we embrace as many of the elements as possible, try to figure out what benefits they bring, and how we can recreate them functionally in our closed aquarium systems.
There are no "flaws" in Nature's work, because Nature doesn't seek to satisfy observers. It seeks to evolve and change and grow. It looks the way it does because it's the sum total of the processes which occur to foster life and evolution.
We as hobbyists need to evolve and change and grow, ourselves.
We need to let go of our long-held beliefs about what truly is considered "beautiful." We need to study and understand the elegant way Nature does things- and just why natural aquatic habitats look the way they do. To look at things in context. To understand what kinds of outside influences, pressures, and threats these habitats face.
And, when we attempt replicate these functions in our aquariums, we're helping to grow this unique segment of the aquarium hobby.
Please make that effort to continue to educate yourself and get really smart about this stuff...And share what you learn on your journey- all of it- the good and the occasional bad. It helps grow the hobby, foster a viable movement, and helps your fellow hobbyists!
Stay studious. Stay thoughtful. Stay inquisitive. Stay creative. Stay engaged...
And Stay Wet.
A couple of days back, I was chatting with a fellow hobbyist who wanted to jump in to something a bit different within the aquarium hobby, but was afraid of the possible consequences-both socially and in his aquariums. He feared criticism from "them", and that just froze him. I felt bad that he was so afraid of criticism from others should he question the "status quo" within the hobby.
Perhaps my story might be helpful to you if you're afraid of such criticisms.
For generations, we've been told in the aquarium hobby that we need to be concerned about the appearance of all kinds of stuff in our tanks, like algae, detritus, and "biocover".
For some strange reason, we as a hobby group seems emphasize stuff like understanding some biological processes, like the nitrogen cycle, yet we've also been told to devote a lot of resources to siphoning, polishing, and scrubbing our tanks to near sterility.
It's a strange dichotomy.
I remember the first few botanical-style tanks I created, almost two decades ago now, would hit that phase early on when biofilms and fungal growths began to appear, and I'd hear my friends telling me, "Yeah, your tank is going to turn into a big pile of shit. Told you that you can't put that stuff in there."
Because that's what they've been told. The prevailing mindset in the hobby was that the appearance of these organisms was an indication of an unsuitable aquarium environment.
Anyone who's studied basic ecology and biology understands that the complete opposite is true. The appearance of these valuable life forms is an indicator that your aquatic environment is ideal to foster a healthy, diverse community of aquatic organisms, including fishes!
Exactly like in Nature.
I remember telling myself that this is what I knew was going to happen. I knew how biofilms and fungal growths appear on "undefended" surfaces, and that they are essentially harmless life forms, exploiting a favorable environment. I knew that fungi appear as they help break down leaves and botanicals. I knew that these are perfectly natural occurrences, and that they typically are transitory and self-limiting to some extent.
Normal for this type of aquarium approach. I knew that they would go away, but I also knew that there would be a period of time when the tank might look like a big pool of slimy shit. Or, rather, it'd look like a pile of slimy shit to those who weren't familiar with these life forms, how they grow, and how the natural aquatic habitats we love so much actually function and appear!
To reassure myself, I would stare for hours at underwater photos taken in the Amazon region, showing decaying leaves, biofilms,and fungi all over the leaf litter. I'd read the studies by researchers like Henderson and Walker, detailing the dynamics of leaf litter zones and how productive and unique they were.
I'd pour over my water quality tests, confirming for myself that everything was okay. It always was. And of course I would watch my fishes for any signs of distress...
I never saw them.
I knew that there wouldn't be any issues, because I created my aquariums with a solid embrace of basic aquatic biology; an understanding that an aquarium is not some sort of underwater art installation, but rather, a living, breathing microcosm of organisms which work together to create a biome..and that the appearance of the aquarium only tells a small part of the story.
I knew that this type of aquatic habitat could be replicated in the aquarium successfully. I realized that it would take understanding, trial and error, and acceptance that the aquariums I created would look fundamentally different than anything I had experienced before.
I knew I might face criticism, scrutiny, and even downright condemnation from some quarters for daring to do something different, and then for labeling what most found totally distasteful, or have been conditioned by "the hobby" for generations to fear, as simply "a routine part of the process."
It's what happens when you venture out into areas of the hobby which are a bit untested. Areas which embrace ideas, aesthetics, practices, and occurrences which have existed far out of the mainstream consciousness of the hobby for so long. Fears develop, naysayers emerge, and warnings are given.
Yet, all of this stuff- ALL of it- is completely normal, well understood and documented by science, and in reality, comprises the aquatic habitats which are so successful and beneficial for fishes in both Nature and the aquarium. We as a hobby have made scant little effort over the years to understand it. And once you commit yourself to studying, understanding, and embracing life on all levels, the world of natural, botanical-style aquariums and its untapped potential opens upon to you.
Mental shifts are required. Along with study, patience, time, and a willingness to look beyond hobby forums, aquarium literature, and aquascaping contests for information. A desire to roll up your sleeves, get in there, ignore the naysayers, and just DO.
Don't be afraid of things because they look different, or somehow contrary to what you've heard or been told by others is "not healthy" or somehow "dangerous." Now sure, you can't obey natural "laws" like the nitrogen cycle, understanding pH, etc.
You can, however, question things you've been told to avoid based on superficial explanations based upon aesthetics.
Stuff that makes you want to understand how life forms such as fungi, for example, arise, multiply, snd contribute to the biome of your aquarium.
Let's think about fungi for a minute...a "poster child" for the new way of embracing Nature as it is.
Fungi reproduce by releasing tiny spores that then germinate on new and hospitable surfaces (ie, pretty much anywhere they damn well please!). These aquatic fungi are involved in the decay of wood and leafy material. And of course, when you submerge terrestrial materials in water, growths of fungi tend to arise. Anyone who's ever "cured" a piece of wood for your aquarium can attest to this!
Fungi tend to colonize wood because it offers them a lot of surface area to thrive and live out their life cycle. And cellulose, hemicellulose, and lignin, the major components of wood and botanical materials, are degraded by fungi which posses enzymes that can digest these materials! Fungi are regarded by biologists to be the dominant organisms associated with decaying leaves in streams, so this gives you some idea as to why we see them in our aquariums, right?
And of course, fishes and invertebrates which live amongst and feed directly upon the fungi and decomposing leaves and botanicals contribute to the breakdown of these materials as well! Aquatic fungi can break down the leaf matrix and make the energy available to feeding animals in these habitats. And look at this little gem I found in my research:
"There is evidence that detritivores selectively feed on conditioned leaves, i.e. those previously colonized by fungi (Suberkropp, 1992; Graca, 1993). Fungi can alter the food quality and palatability of leaf detritus, aecting shredder growth rates. Animals that feed on a diet rich in fungi have higher growth rates and fecundity than those fed on poorly colonized leaves. Some shredders prefer to feed on leaves that are colonized by fungi, whereas others consume fungal mycelium selectively..."
"Conditioned" leaves, in this context, are those which have been previously colonized by fungi! They make the energy within the leaves and botanicals more available to higher organisms like fishes and invertebrates!
The aquatic fungi which will typically decompose leaf litter and wood are the group known as “aquatic hyphomycetes”. Another group of specialists, "aero-aquatic hyphomycetes," colonize submerged plant detritus in stagnant and slow- flowing waters, like shallow ponds, puddles, and flooded forest areas. Fungal communities differ between various environments, such as streams, shallow lakes and wetlands, deep lakes, and other habitats such as salt lakes and estuaries.
And we see them in our own tanks all the time, don't we? Sure, it's easy to get scared by this stuff...and surprisingly, it's even easier to exploit it as a food source for your animals! We just have to make that mental shift... As the expression goes, "when life gives you lemons, make lemonade!"
I knew when I started Tannin that I had to "walk the walk." I had to explain by showing my tanks, my work, and giving fellow hobbyists the information, advice, and support they needed in order to confidently set out on their own foray into this interesting hobby path.
I'm no hero. Not trying to portray myself as a visionary.
The point of sharing my personal experience is to show you that trying new stuff in the hobby does carry risk, fear, and challenge, but that you can and will persevere if you believe. If you push through. IF you don't fear setbacks, issues, criticisms from naysayers.
You have to try. In my case, the the idea of throwing various botanical items into aquariums is not my invention. It's not a totally new thing. People have done what I've done before. Maybe not as obsessively or thoroughly presented (and maybe they haven't built a business around the idea!), but it's been done many, many times.
The fact is, we can and should all take these kinds of journeys.
Stay the course. Don't be afraid. Open your mind. Study what is happening. Draw parallels to the natural aquatic ecosystems of the world. Look at this "evolution" process with wonder, awe, and courage.
And know that the pile of decomposing leaves, fungal growth, and detritus that you're looking at now is just a steppingstone on the journey to an aquarium which embrace nature in every conceivable way.
Stay brave. Stay curious. Stay diligent. Stay observant...
And Stay Wet.
There is something incredibly compelling about the way terrestrial trees and shrubs interact with the aquatic environment. This is a surprisingly dynamic, highly inter-dependent relationship which has rarely been discussed in aquarium circles.
Let's have that talk!
We have talked a lot about roots before...They are structures which are so important in so many ways to these ecosystems, in both their terrestrial and aquatic phases.
Not only do they help "secure the soils" from falling away, they foster epiphytic algae, fungal growth, and biofilms, which supplement the foods of the resident fishes. And of course, they provide a physical habitat for fishes to forage, seek shelter, and reproduce among. In short, these roots create a unique "microhabitat" which harbors a diversity of life.
And they look pretty aesthetically cool, too!
So yeah- this makes them an irresistible subject for a natural-looking- and functioning- aquascape!. And relatively easy to execute, too!
With a variety of interesting natural materials readily available to us as hobbyists, it's easier than ever to recreate these habitats in as detailed a version as you care to do.
As usual with my ramblings, this blog has become yet another homage to roots and other forest features, and how they function in the transitional aquatic habitats we love so much.
One of the foundational root types that we can replicate in or aquarium works what botanists call "buttress roots." Not only are these interesting structures to replicate in our aquariums, they are an important component of the ecosystems which make up the flooded forests, particularly in areas like Amazonia.
Buttress roots are large, very wide roots that help keep shallow-rooted forest trees from toppling over. They are commonly associated with nutrient-poor soils (you know, like the kinds you see in the igapo or varzea ecosytems). These roots also serve to take uptake nutrients are available in these podzolic soils.
The buttress roots of various species of forest trees often weave in and out of each other horizontally, and create a vast network which serves to keep many trees in the forest from toppling over. And since these habitats often flood during the rainy season, buttress roots help stabilize the trees and retain soils during this inundation.
Isn't that interesting? Even the trees have made adaptations over eons which allow them to survive under these harsh conditions! As you might suspect, the "white-water" flooded forests (Varzea) tend to be richer in species diversity and density than the less nutrient-dense blackwater-flooded Igapo forests. Seems like everything in these ecosystems is a function of nutrient availability, isn't it?
And the sandy soil which comprises these habitats is low in nutrients, such as phosphorus, potassium, calcium, and magnesium. Ecologists will tell you that the soil also has a "high infection rate", or density, of fungi, and consists of a lot of fine roots in the upper layer of the soil.
The network of fine roots helps these forests uptake nutrients in these nutrient- poor conditions. And even more interesting, studies have shown that decomposition of materials can take several years in the deep litter layer on the forest floor.
In addition to being nutrient poor, the sandy soil does not retain water very well, which can lead to drought after the inundation period is over. It's another example of the intricate relationship between land and water, and the way terrestrial and aquatic habitats work together.
Because the flood pulses are so predictable, eons of this process has led to adaptations by various forest trees to withstand them, as well as to depend upon various species of fishes ('frugivores") to help disperse seeds throughout the forest by consuming and pooping them out!
Ecologists have further determined that the distribution of various species of trees in these forests may be largely determined by the ability of their seedlings to tolerate periods of submergence and limited light that penetrates the canopy through the water column.
(Cariniana legalis tree. Image by mauroguanandi, used under CC BY 2.0)
In fact, in remarkable adaptation to this environment, seedlings may be completely submerged for several months, and many species can tolerate several weeks of complete submergence in a state of "rest." Most species in these forests tend to grow during the times year when the forests are flooded, and tend to bear fruit and flower when the waters start to recede.
It's all about adaptation to this incredible, highly variable habitat.
We talk a lot about food webs in these habitats and how to replicate some of their attributes in our aquariums. Here's another insight into the food webs of these flooded forest habitats to consider, from a paper I found by researcher Mauricio Camargo Zorro:
"Both algae and aquatic macrophytes enter in aquatic food webs mostly in form of detritus (fine and coarse particulate organic matter) or being transported by water flow and settling onto substrates (Winemiller 2004). Particulate organic matter in the stream of rapids and waterfalls is mostly associated with biofilm and epilithic diatoms that grow on rocks, submerged wood, and herbaceous plants and compose the main energy sources for macro invertebrates and other trophic links (Camargo 2009a)."
A lot there, I know. What this does is give us some ideas about facilitating the "in situ" production of supplementary food sources in our aquariums.
This was what inspired me in a recent home "planted" blackwater aquarium. The interaction between the terrestrial elements and the aquatic ones. Allowing terrestrial leaves to accumulate naturally among the "tree root structure" we have created fosters this more natural-functioning environment.
As these leaves begin to soften and ultimately break down, they foster microbial growth, biofilms, and fungal growths- all of which will provide supplemental foods for the resident fishes...just like what happens in Nature.
Facilitating these processes- allowing the materials to accumulate naturally and break down "in situ" is a key component of replicating and supporting these microhabitats in our aquariums. The typical aquarium hardscape- artistic and beautiful as it might be, generally replicates the most superficial aesthetic aspects of such habitats, and tends to overlook their function- and the reasons why such habitats form.
Replicating forest structures- like buttress roots and their functions- really helps facilitate more natural biological processes, functions, and behaviors in our fishes!
The possibilities are endless here! And, as always, the aesthetics are a "collateral benefit" of the process.
And of course, I think it's a call for us to employ some bigger, thicker pieces of wood in our tanks! Now, sure, I can hear some groans. I mean, big, heavy wood has some disadvantages in an aquarium. First, the damn things are...well- BIG- taking up a lot of physical space, and in our case, precious water volume. And the "scale" is a bit different. And, of course, a big, heavy piece of wood is kind of pricy. And physically cumbersome for some.
However, the use of larger pieces of wood- or several pieces of wood aggregated together- can create really interesting structures which can replicate the form and function of buttress roots in the aquarium.
At the very least, you can try a fairly large piece of aquatic wood (or several smaller pieces, aggregated to form one large piece) some time. I think you might find this sort of arrangement quite fascinating to play with!
Arrange the wood in such a way as to break up the tank space and give the impression that it simply rooted naturally. Let it create barriers for fishes to swim into, and disrupt water flow patterns. Allow it to "cultivate" fungal growth and biofilms on its surfaces, and small pockets where leaves, botanicals, substrate materials, and...detritus can collect.
This is exactly what happens in Nature.
It's fascinating and important for us to understand- at least on a superficial level- the concept of replicating some of the structures and features of these transitional habitats, such as flooded forest floors.
By understanding how these structures work, why the exist, and how they provide a benefit to the organisms which live among them, we will be in an excellent position to incorporate exciting features- such as buttress roots-into our future aquariums!
Stay inspired. Stay educated. Stay bold. Stay creative. Stay thoughtful...
And Stay Wet.