The Tint

The little Tetra that can..A deeper dive.

One of the things I enjoy most in the aquarium hobby is studying the ecology of the natural habitats of our fishes. I've found over the years that you can find out so much about the fish by understanding a bit about where it comes from. 

When it comes to characins, there are few more widely known and loved in the hobby than the Neon Tetra, Paracheirodon inessi. This little fish has been the "gateway drug" for generations of tropical fish hobbyists, providing a colorful, exotic look into Nature's magnificent creations.

Of course, there other members of the genus Paracheirodon which hobbyists have become enamored with, such as the diminutive, yet equally alluring P. simulans, the "Green Neon Tetra." Topping out at around 3/4" (about 2cm) in length, it's certainly deserving of the hobby label of "nano fish!"

You can keep these little guys in nice -sized aggregations..I wouldn't necessarily call them "schools", because, as our friend Ivan Mikolji beautifully observes, "In an aquarium P. simulans seem to be all over the place, each one going wherever it pleases and turning greener than when they are in the wild."

This cool little fish is one of my fave of what I call "Petit Tetras." Hailing from remote regions in the Upper Rio Negro and Orinoco regions of Brazil and Colombia, this fish is a real showstopper! According to ichthyologist Jacques Gery, the type locality of this fish is the Rio Jufaris, a small tributary of the Rio Negro in Amazonas State.

One of the rather cool highlights of this fish is that it is found exclusively in blackwater habitats. Specifically, they are known to occur in  habitats called "Palm Swamps"( locally known as "campos") in the middle Rio Negro. These are pretty cool shallow water environments. Interestingly, P. simulans doesn't migrate out of these shallow water habitats ( also called "woody herbaceous campinas" by aquatic ecologists) like the Neon Tetra (P. axelrodi) does. It stays to these habitats for its entire lifespan.

These "campo" habitats are essentially large depressions which do not drain easily because of the elevated water table and the presence of a soil structure, created by our fave soil, hydromorphic podzol! "Hydromorphic" refers to s soil having characteristics that are developed when there is excess water all or part of the time. 

(Image by G. Durigan)

So, if you really want to get hardcore in recreating this habitat, you'd use immersion-tolerant terrestrial plants, such as Spathanthus unilateralis, Everardia montana, Scleria microcarpa, and small patches of shrubs such as Macairea viscosa, Tococa sp. and Macrosamanea simabifoli. And grasses, like Trachypogon. 

Of course, our fave palm,  Mauritia flexuosa and its common companion, Bactris campestris round out the native vegetation. Now, the big question is, can you find any of these plants? Perhaps...More likely, you could find substitutes. 

Just Google that shit! Tons to learn about those plants!

These habitats are typically choked with roots and plant parts, and the bottom is covered with leaves...This is right up our alley, right?

Of course, if you really want to be a "baller" and replicate the natural habitat of these fishes as accurately as possible, it helps to have some information to go on! So, here are the environmental parameters from these "campo" habitats based on a couple of studies I found:

The dissolved oxygen levels average around 2.1 mg/l, and a pH ranging from 4.7-4.3. KH values are typically less than 20mg/L, and the GH generally less than 10mg/L. The conductivity is pretty low. T

he water depth in these habitats, based on one study I encountered, ranged from as shallow as about 6 inches (15cm) to about 27 inches (67cm) on the deeper range. The average depth in the study was about 15" (38cm). This is pretty cool for us hobbyists, right? I mean, we can utilize all sorts of aquariums and accurately recreate the depth of the habitats which P. simulans comes from!

Now, as aquarists, we often hear that P. simulans needs fairly high water temperatures, and the field studies I found for this fish this  confirm this.

Average daily minimum water temperature of P. simulans habitats in the middle Rio Negro was about 79.7 F (26.5 C) between September and February (the end of the rainy season and part of the dry season). The average daily maximum water temperature during the same period averaged about 81 degrees F (27.7 C). Temperatures as low as 76 degrees' (24.6 C) and as high as 95 degrees F (35.2 C) were tolerated by P. simulans with no mortality noted by the researchers.

Bottom line, you biotope purists? Keep the temperature between 79-81 degrees F (approx. 26 C-27C).

Researchers have postulated that a thermal tolerance to high water temperatures may have developed in P. simulans as these shallow "campos" became its only real aquatic habitat.

The fish preys upon that beloved catchall of "micro crustaceans" and insect larvae as its exclusive diet. Specifically, small aquatic annelids, such as larvae of Chironomidae (hey, that's the "Blood Worm!") which are also found among the substratum, the leaves and branches. 

Now, if you're wondering what would be good foods to represent this fish's natural diet, you can't go wrong with stuff like Daphnia and other copepods. Small stuff makes the most sense, because of the small size of the fish and its mouthparts.

This fish would be a great candidate for an "Urban Igapo" style aquarium, in which rich soil, reminiscent of the podzols found in this habitat is use, along with terrestrial vegetation. You could do a pretty accurate representation of this habitat utilizing these techniques and substrates, and simply forgoing the wet/dry "seasonal cycles" in your management of the system.

There are a lot of possibilities here. 

One of the most enjoyable and effective approaches I've taken to keeping this fish was a "leaf litter only" system (which we've written about extensively here. Not only did it provide many of the characteristics of the wild habitat (leaves, warm water temperatures, minimal water movement, and soft, acidic water).

I'm preparing for a second run at replicating this fish's habitat, this time with a different substrate and a "root tangle" approach using Melastoma Root and "Borneo Root". I am really looking forward to seeing if there are any behavioral differences with a more densely packed hardscape configuration, as opposed to the completely open "no scape" that the previous version offered.

Now, the pH issue is something we all have to think about and experiment with if we really want to go as accurately as possible.

I know of few hobbyists who have ventured into the "sub 5" range with pH, so that's a real interesting challenge and approach; not for the feint of heart. It can be done, it simply requires a greater understanding of water chemistry and the techniques and materials designed to get you there.

Life with botanicals...

There is something very pure and evocative-even a bit "uncomfortable" about utilizing botanical materials in the aquarium. Selecting, preparing, and utilizing them is more than just a practice- it's an experience. A journey.One which we can all take- and all benefit from.

Right along with our fishes, of course!

The energy and creativity that you bring with you on the journey tends to become amplified during the experience. We don’t want everyone walking away feeling the same thing, quite the opposite actually. 

That uniqueness is a large part of the experience.

The experience is largely about discovery. And today's piece is a bit about some of the interesting discoveries- expectations, and revelations that we've learned along the way during our "life with botanicals!"

Our aquariums evolve, as do the materials within them.

If we think of an aquarium as we do a natural aquatic ecosystem, it's certainly realistic to assume that some of the materials in the ecosystem will change, re-distribute, or completely decompose over time.

Botanicals are not "forever" aquascaping materials. We consider them ephemeral in nature. They will soften, break down, and otherwise decompose over time. Some materials, like leaves- particularly Catappa and Guava, will break down more rapidly than others, and if you're like our friend Jeff Senske of Aquaiuim Design Group, and like the look of intact leaves versus partially decomposed ones, you'll want to replace them more frequently; typically on the order of every three weeks or so, in order to have more-or-less "intact" leaves in your tank.

On the other hand, if you're like me, and enjoy the more natural look that occurs as the leaves break down, just keep 'em in. You may need to remove some materials if you find fungal growth, biofilm, or other growth unsightly or otherwise untenable. However, if you've made that "mental shift" and can tolerate the stuff, just let them be and enjoy!

Botanicals like the really hard seed pods (Sterculia Pods", "Cariniana Pods", "Afzelia Pods"), etc., can last for many, many months, and generally will soften on their interiors long before any decomposition occurs on the exterior "shell" of he botanical.  In fact, they'll typically recruit biofilms, which almost seem to serve as a sort of "protective cover" that preserves them.

Often times, fishes like Plecos, Otocinculus catfish, loaches, Headstanders, and bottom-dwelling fishes will rasp or pick at the decomposing botanicals, which further speeds up the process. Others, like Caridina shrimp, Apistos, characins, and others, will pick at biofilms covering the interior and exterior of various botanicals, as well as at the microfauna which live among them, just as they do in Nature. 

We receive a lot of questions about which botanicals will "tint the water the darkest" or whatever. Cool questions. Well, here's the deal:  Virtually all botanical materials will impact the color of the water. You'll find, as we have, that different materials will impart different colors into the water. It will typically be clear, but with a golden, brownish, or reddish tint.

The degree of tint imparted will be determined by various factors, such as how much of the materials you use in your tank, how long they were boiled and soaked during the preparation process, and how much water movement is in your system.However, rest assured, almost any botanical materials you submerge in your tank will impart some color to the water.

Unfortunately, since these are natural materials, there is no set "X number of leaves/pods per ___ gallons of aquarium capacity", and you'll have to use your judgement as to how much is too much! It's as much of an "art" as it is a "science!"

Now, If you really dislike the "tint", but love the look of the botanicals you can mitigate some of this by employing a lmuch onger "post-boil" soaking period- like over a week. Keep changing the water in your soaking container daily, which will help eliminate some of the accumulating organics, as well as to help you to determine the length of time that you need to keep soaking the botanicals to minimize the tint.

Of course, it's far easier to simply employ chemical filtration media, such as activated carbon, and/or synthetic adsorbents such as Seachem Purigen, to help eliminate a good portion of the excess discoloration within the display aquarium where the botanicals will ultimately "reside."

Another interesting phenomenon about "living with your botanicals" is that they will "redistribute" throughout the aquarium. They're being moved around by both current and the activities of fishes, as well as during our maintenance activities, etc. This is, not surprisingly, very similar to what occurs in Nature, where various events carry materials like seed pods, branches, leaves, etc. to various locales within a given body of water. In our opinion, this movement of materials, along with the natural and "assisted" decomposition that occurs, will contribute to a surprisingly dynamic environment!

Your aquarium water may appear turbid at various times. We are pretty comfortable with this idea; however, some of you may not be. As bacteria act to break down botanical materials, they may impart a bit of "cloudiness" into the the water. Also, materials such as lignin and good old terrestrial soils/silt find their way into our tanks at times.

Some of these inputs, such as soils- are intentional! Others are the unintended by-product of the materials we use, The look is definitely different than what we as aquarists have been indoctrinated to accept as "normal." One of my good friends, and a botanical-style aquarium freak, calls this phenomenon  "flavor"- and we see it as an ultimate expression of a truly natural-looking aquarium.

Yeah, the water itself becomes part of the attraction. The color, the "texture", and the clarity  of the water are as engrossing and fascinating as the materials which affect it.

Need a bit more convincing to embrace the charm of the water itself in botanical-style aquariums?

Simply look at a natural underwater habitat, such as an igapo or flooded varzea grassland, and see for yourself the allure of these dynamic habitats, and how they're ripe for replication in the aquarium. You'll understand how the terrestrial materials impact the now aquatic environment- fundamental to the philosophy of the botanical-style aquarium.

Speaking of the impact of terrestrial materials on the aquatic habitat- remember, too, that just like in Nature, if new botanicals are added into the aquarium as others break down, you'll have more-or-less continuous influx of materials to help provide enrichment to the aquarium environment. This type of "renewal" creates a very dynamic, ever-changing physical environment, while helping keep water chemistry changes to a minimum.

The fishes in your system may ultimately display many interesting behaviors, such as foraging activities, territorial defense, and even spawning, as a result of this regular influx of "fresh" aquatic botanicals. You could even get pretty creative, and attempt to replicate seasonal "wet" and "dry" times by adding new materials at specified times throughout the year...The possibilities here are as diverse and interesting as the range of materials that we have to play with!

It's all a part of your "life with botanicals"- an ever-changing, always interesting dynamic that can impact your fishes in so many beneficial ways.

Stay dedicated. Stay excited. Stay engaged. Stay resourceful...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

A bit of a problem...And how we're doing our part to fix it.

The aquarium hobby is certainly one of those endeavors which pulls in all sorts of people, with widely diverse experience, interests, and abilities. And, because of this "wide net" that the hobby casts, we have a huge assortment of possibilities for success.

If you've been in the hobby for some time, as I have (like, all my life), you start noticing trends, or more specifically, changes in practices, attitudes, and interest levels. I've noticed a troubling one lately.

In a world where people are supposedly not able to retain more than 280 characters of information, and where there is a apparently a "hack" for pretty much everything,  I wonder if have we simply have lost the ability to absorb information on things that are not considered “relevant” to our immediate goal. I say this not in a sarcastic manner, but in a thoughtful, measured one. I'm baffled by hobbyists who want to try something new and simply do next to no research or self-education prior to trying it.

Like, WTF?

When you read some of the posts on Facebook or other sites, where a hobbyist asks a question which makes it obvious that they failed to grasp even the most fundamental aspects of their "area of interest", yet jumped in head-first into this "new thing", it just makes you wonder!  I mean, if the immediate goal is to have "a great looking tank", it seems to me that some hobbyists apparently don’t want to take the time to learn the groundwork that it takes to get there and to sustain the system on a long-term basis. I suppose that it’s far more interesting- and apparently, immediately gratifying- for some hobbyists to learn about what gadgets or products can get us where we want, and what fishes are available to complete the project quickly.

This is a bit of a problem.

We perpetuate this by well- dumbing everything down. We feature the superficial aspects of the hobby- how cool the tanks look, the overly-stylized images of aquascaping contest winners, etc., while failing to get people to grasp the basics. We often see these threads that emphasize the equipment or various brands of stuff used, complete with all of the appropriate hashtags for discoverability.

I mean, I get that part. Society has shifted, and discovering content is important. It's just sort of interesting to me to see this elevated in importance over stuff like, oh- I don't know- a discussion of how the damn system works, what the inspiration for it was, etc., etc.

Just an emphasis on too much of the "finished product" and a complete absence of information about how to get there. We need to address this. 

Then there are those “build threads” you see on various forums (it's especially "rampant" in the reef side of the hobby). In many of these threads, you’ll see a detailed run down of the equipment, shots of the assembly, the “solutions” to the problems encountered along the way (usually more expensive equipment purchases). You’ll see pics of the finished tanks…But not much of the more "interesting" phases of their existence.

All very interesting and helpful, but the “weirdness” starts when, in the middle of the threads, you’ll see the “builder” asking about why he’s experiencing a massive algae outbreak, or why all of the Apistogramma, plants or coral frags he just added are dying in this brand new, state-of-the-art tank. Questions and ensuing discussions that are so "Aquarium 101" that they make you wonder why this ill-informed, yet apparently well-healed individual went off on a 5-figure “joyride”, building a dream tank with an apparent complete ignorance of many of the hobby fundamentals. And sadly, the hobbyist sometimes just...quits. 

I’m often dumbfounded at the incredible lack of hobby basics many of these people show. Just because you’re a great DIY guy, and have disposable income to buy everything you see advertised on line for your 400-gallon tank, it doesn’t make you a knowledgeable or experienced aquarist. It just doesn’t.

Okay, I’m sounding very cynical. And perhaps I am. But the evidence is out there in abundance…and it’s kind of discouraging at times.

Look, I’m not trying to be the self-appointed "guardian of the hobby." I’m not calling us out. I’m simply asking for us to look at this stuff realistically, however. To question our habits. No one has a right to tell anyone that what they are doing is not the right way, but we do have to instill upon the newbie the importance of understanding the basics.

Like many other vendors, I offer  products to people and don’t educate them on every single aspect of aquatic husbandry. I spend scant little time discussing the most basic aspects of the aquarium hobby. I have to make the assumption that an aquarists jumping in to the botanical-style aquarium game at least has some prior hobby experience and a grasp of the fundamentals. Perhaps it's too much of an assumption?

Personally, I'm not interested in re-hashing "Aquarium Keeping 101"- there are plenty of amazing hobby resources out there for that stuff. I prefer to share and disseminate information as it pertains to our unique hobby speciality. Quite frankly, I think we've done a pretty good job of it over the past 5 years or so, too.

Educating and informing is every bit as important as "selling" and inspiring fellow hobbyists on this stuff. When we started Tannin, I knew that we were heading onto an area of the hobby that was replete with speculation, myths, and downright misinformation- if you could find anything about it out there at all. So, we started out from day one, sharing all sorts of information about our little hobby speciality. 

It’s hard to do that. I do write lots of blogs and articles, and lecture all over the world, so I know I’m doing something to reach some people…but not enough. I need to do better. I probably need to write more about basic sort of stuff than I do about whatever the heck is on my mind? Dunno. I do know that we all need to tell hobbyists like it is, without sugar coating everything. There WILL be decomposition. There WILL be biofilms! Shit like that. We have to keep talking about all aspects of this stuff.

Sometimes, it's controversial. Other times, it's speculative. Sometimes, we simply don't have the answers- we just have the observations based upon our experience, so we share those. We hypothesize when we feel comfortable. We've grown along with our community, sharing our ideas and experiences in as unfiltered a manner as possible. Our ideas and information has become more sophisticated and useful as we've evolved, and as global feedback has come in.

Thanks to YOU- our community, we've all created a movement in the hobby.

I remember when I started Tannin Aquatics, I was determined to share my passion for using all sorts of botanicals and leaves to create what I feel are a profoundly different type of "natural aquarium" than the sanitized, polished, aquarium-as-a-canvas model that's been preferred to us over the past decade or so as the shit. I knew that there would be aquarists who didn't "get it"- aquarists who would focus on the perceived "negatives", like decomposition, issues, maintenance, having to prepare everything before use, etc. Stuff that is actually the important, positive fundamental "cannon" of what we do.

I KNEW that there would be people who might kill their fishes by adding lots of botanicals to their established systems without reading and following the instructions concerning preparation, cadence, and what to expect. I knew there would be people who would criticize the idea, "edit" the processes or recommended "best practices", talk negatively about the approach and generally scoff and downplay what they didn't know, understand, or do.

It's human nature whenever you give people something a bit different to play with...They want to go from 0-100 in like one day. And I knew that some of these people would go out on social media and attempt to trash the whole idea after they failed. This, despite all of our instructions, information, and pleas to follow the guidelines we suggested. 

That's how it goes in the hobby sometimes. When you're trying new things, some people are really eager to get into them...but not all are eager to "look before they leap." That's why reef aquariums seem to be so challenging...even mysterious- to some people. It seems like the rewards are so great- so cool...they want in. Now. And there are all of these cool gadgets and chemicals and stuff that make it super easy!

Regrettably, many manufacturers and vendors over the years have fed this narrative by over-hyping their products and conveniently glossing over the potential pitfalls of using them.

We don't. We share it all.

I guess this is why I get pissed off as fuck when I see  someone out there in forums or wherever jump to some speculative "conclusion" without the obvious firsthand experience about what we do and try to heap us into the "fluff marketing/PR" category of brands which make generic, seemingly spectacular claims about their products and ideas.

WE DON'T. We never have. We never will. Search all 600 or so of our blogs, the dozen or so hobby magazine articles we've written on this idea, and try to find a word of marketing hyperbole or outrageous claims about our products or this idea of botanical-style aquariums. You won't. It's not in our "DNA." 

Now, of course, it goes with the territory- the skepticism, constructive criticisms, and outright accusations. We have to swallow our pride sometimes and just listen,  and decide if we're going to respond in some direct way...or to just keep our heads down and do what we do. I guess this very blog is another "marker" we're laying down to counteract that sort of thing. 

It's a continuous process that we as aquarium hobby proponents and brands need to do. We need to address all of this stuff. Good and bad.

Because NOT sharing the potential negatives is a bad thing. I'm super-proud that we've consistently elevated realistic discussions about unpopular topics related to our hobby sector. Yeah, we literally have blog and podcast titles like, "How to Avoid Screwing Up Your Tank and Killing all of Your Fishes with Botanicals" , or "There Will be Decomposition", or "Celebrating The Slimy Stuff."

We continuously use all of our products- often deliberately, in ways we'd never, ever recommend you try. We've literally set up systems to see how far we can push it, and to see what kind of consequences could happen from misusing them.

We're going to keep doing that. Because, when you're pushing unusual and exotic ideas, many of which have no precedent or "settled science" behind them, you need to continuously document experiences and share discoveries- the good, the bad- and the ugly. It's how we will continue to do our share to advance this hobby speciality and push beyond what's currently accepted.

This is my call to all of the members of our global community- Hobbyists, authors, vendors, manufacturers:

Go beyond the superficial, "Insta-ready" splash, and have thoughtful, realistic, and frank discussions with your fellow hobbyists about all aspects of what we do. Stress fundamentals, the process...the journey.

We owe it to the hobby, our fellow fish geeks...and most important- the plants and animals that we love so much.

Stay honest. Stay strong. Stay bold. Stay thoughtful...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

"The Pasta Sauce Analogy" and Aquatic Substrates...

We talk about soem weird things around here, don't we? 

I admit, we have some rather "unorthodox" approaches to stuff. However, I think. a lot of what we are doing here is becoming more "mainstream" all the time..Or, at least, a lot of this stuff is getting more consideration than it has in the past!

Back in 2015, we talked about the idea of "substrate enrichment" in botanical-style aquariums. In other words, adding botanical materials to the more traditional substrates of sand, etc. Now, at first glance, this idea seems rather "normal" in many respects. I mean, planted aquarium enthusiasts have been adding various supplements to their substrates for decades, with the intention of providing beneficial trace elements and nutrients for plants.

Yet, we're talking about enriching the substrate for the purpose of providing tannins, humic substances, and nutrition- for microbial and crustacean life forms that could reside in the substrate. Not primarily for aquatic plants.

When you examine the substrates found in many natural habitats, they often appear to be a mixture of a variety of materials, including sands, sediments, muds, clays, and botanical materials. These materials not only look different- they function in unique ways, not only influencing the water chemistry, but the biology and ecology of the aquatic systems as well.

Now, in Nature, there are numerous factors which contribute to the composition of substrates in wild aquatic habitats, including geology, the flow velocities of the body of water, the surrounding topography, the seasonal variations in water level (ie; inundation/dessication cycles), and accumulation of materials from the surrounding terrestrial environment.

Nature utilizes almost everything at her disposal in order to create and maintain aquatic ecosystems. So, why do we as hobbyists, who want to create the most realistic approximations of wild habitats possible, just sort of "mail it in" when it comes to substrate? I mean, just open a bag of _____________ sand or whatever, and call it a day and move on to he more "exciting" parts of our tank?

I think we just rely on the commercially available stuff and that's that.

Now, in defense of the manufacturers of sands and gravels for aquarium use- I love what they do, and what they have available. These items are of generally excellent quality, provide a wide range of choices for a variety of applications, and are readily available.

However, IMHO, they are a great "starting point" for creating more dynamic substrates for our aquariums. Kind of like tomato puree is to pasta sauce...a beginning! Sure, you can use just the puree and enjoy it as your sauce, but isn't it always better to add a bit of "this and that" and build on the "base"to create something better?

Totally.

(Damn, it's 7:00AM here in L.A., and now I'm craving Penne...WTF?)

That, in a nutshell, is my theory of aquarium substrates. 

We can do a bit better.

We will do better with the imminent first release of our "NatureBase" substrate line!

Okay, back to the wild for a second...Let's look at how natural substrates form.

Now, in many of the tropical regions we admire, the basic substrate is often referred to simply as "fine, white sand" in most scientific papers- typically, but not necessarily a silica of some sort. And of course, other locations have slightly larger grain sizes of other pulverized stones and such. Still others are comprised of sediments which wash down from higher elevations during seasonal rains.

Deep rivers will typically have different substrate compositions than say, marginal streams or floodplain lakes, or even flooded forests. In the Amazon region, a huge percentage of the sediment and materials which comprise the substrates are from the Andes mountains, where they are transported down into the lower elevations by water flow.

This has huge foundational impact on the chemistry of the waters in the region. This process builds the fertile floodplain soils along Andean tributaries and the main stem of The Amazon.

There is a whole science around aquatic substrates and their morphology, formation, and accumulation- I don't pretend to know an iota about it other than skimming Marine biology/hydrology books and papers from time to time.

However, merely exploring the information available on the tropical aquatic habitats we love so much- even just looking long and hard at some good underwater pics of them- can give us some good ideas!

First off, in some areas- particularly streams which run through rain forests and such, the substrates are often simply a terrestrial soil of some sort. A finer, darker-colored sediment or soil is not uncommon. The water chemistry- indeed, "blackwater" itself, is based on the ionic, mineral, and physical concentrations of terrestrial materials that are dissolved into the water. And the degree to which these materials disperse into the aquatic environments vary based on water velocities, time of year, and other factors, as touched on above. 

Meandering lowland rivers maintain their sediment loads by continually re-suspending and depositing materials within their channels- a key point when we consider how these materials remain in the aquatic ecosystems.

Okay, I could go on and on with my amateur, highly un-scientific review of substrates in Amazonia and elsewhere, but you get the point!

There is more to the substrate materials found in Nature than just "sand." That's the biggest takeaway here! So, as hobbyists, we have more options and inspiration to to draw on to create more compelling functional substrates in our aquariums!

What that means to us is (taking into account the "pasta sauce analogy", of course) is that we should consider mixing other materials into our basic aquarium sands. For example, you could mix aquatic plant soils into you sand. You could experiment with materials such as clay, or other mineral/plant-based components of varying particle sizes. 

Obviously, your substrate will look a lot different than the "typical" aquarium substrate when you start mixing materials. Your overall aquarium will, too. And that's a good thing, IMHO. I played around with this a lot in my office brackish water Mangrove aquarium, where the substrate played an integral functional role in the aquarium, as well as an aesthetic one...

If you start with one of our "sedimented" substrates, which already is intended to mimic the look and characteristics of natural aquatic substrates, you're already a little ahead of the curve. However, you can apply this idea to just about any type of aquarium substrate, 

A combination of finely crushed leaves, bits of botanicals, small twigs, etc. can form the basis for a more "biologically active" and even productive substrate. As these materials break down, they are colonized by fungi and biofilms, and impart  tannins, lignin, and other sources of carbon into the water to fuel a variety of microbial growth.

And of course, larger crustaceans and even fishes will consume the organisms which live in this "matrix", as well as possibly consuming some of the detritus from the decomposing leaves themselves.

Its a very different looking- and functioning- substrate, for sure. At the risk of sounding too commercial here, suffice it to say, we have a whole damn section on our site called "Substrate Additives" for the very purpose of facilitating such geeky experiments! 

This stuff is THAT interesting to me...It's wide open for lots of experimentations, evolutions, and evenbreakthroughs.

Look to Nature, again.

Now, of course, you're running an aquarium, not managing a stretch of open wild river or stream. Duh. The dynamics of closed systems are a bit different! However, the forces of Nature and Her "laws" will  always apply. It's up to us as aquarists to make the effort to understand them and work with them, instead of against them.

Approaches, observations, management...and algae!

We focus a whole lot about the practices involved in setting up botanical-style aquariums, the nuances in their evolution, and the "best practices" involved in managing them. However one of the things that we're overdue for another discussion on is the long term expectations of what happens in such a system.

Specifically, what happens in an aquarium where we have this enormous amount of botanical materials breaking down?

First off, let's clarify some stuff. Despite the seemingly laissez-faire style of "a whole lotta stuff" accumulating in the aquarium, it's not just, "Drop in leaves and forget." There is a fair amount of technique there. Technique, married with long-utilized common-sense aquarium husbandry practices.

I am a big believer in stability, and deploying patience, using time-honored nutrient control/export techniques, and applying a healthy dose of observation and common sense all contribute to the ultimate stability and success of our blackwater/botanical-style aquariums- just as they would to any other type of system.

One of the things that we all experience with these types of systems is an initial burst of tint-producing tannins, which likely will provide a significant amount of "visible tint" to the water. If you're not using activated carbon or some other filtration media, tis tint will be more pronounced and likely last longer than if you're actively removing it with these materials!

You might also experience a bit of initial cloudiness...this could either be physical dust or other materials released from the tissues botanicals, or even a burst of bacteria/microorganisms. Not really sure why, but it usually passes quickly with minimal, if any intervention on your part. Oh, and not everyone experiences this...often this is a phenomenon which seems to happen in brand new tanks...so it might not even be directly attributable to the presence of the botanicals (well, at least not 100%). Could be the sand, or other dust/dirt from the other hardscape materials or the tank itself.

And of course, as we've discussed, it's perfectly normal for the water in botanical-style aquariums to have a little bit of "texture" to it- a sort of normal by-product of the breakdown of the materials we use.

While we're on the subject of new tanks, one of the things I've noticed about my botanical-style/blackwater aquariums is that they "cycle" very quickly. Like, often in less than a week. Why? I think it's got something to do with a large influx of botanical materials in a new system. The same factors that would endanger an established system might simply contribute to a rapid growth of bacteria.

Interestingly, over the years, I've also found that nitrate accumulation tends to be almost nonexistent in my botanical-style aquairums. Now, I don't know if that's something which you've noticed, too? I simply have never seen a nitrate accumulation more than 0.2mg/L!

Despite what I hypothesized would happen in my early years of playing with this style of aquarium, when I really got into blackwater, botanical-style aquariums, I found that they almost always produce little to no detectible nitrate, despite utilizing a lot of botanical material within the tank that was breaking down. I would have thought, at least on the surface, that there would be some detectible elevated nitrate. Now, this is interesting, but I'm not the only one who has reported this. Many of you have.

My hypothesis is that, yes, the material is breaking down, and contributing to the biological "load" of the system- but with an abundance of microorganisms living in, on, and among the botanical materials in the aquarium, and with regular frequent water changes, there is a very efficient processing of nutrients occurring.

This is purely speculation on my part, but I think it's as good a guess as any, based on the repeated similar results I've achieved in pretty much every single blackwater/botanical-style aquarium I've kept for the last 7 or 8 years!

I'm sure that a more sophisticated explanation, revolving around the presence of "on- board carbon sources" and other biological processes is the reason. I think that we're sort of looking at a freshwater equivalent of a reef aquarium in many respects, where, instead of "live rock", a lot of the microbial population and biological processes occur within and upon the surfaces of the botanicals themselves.

Almost like "biopellets" in a reef tank, perhaps the botanicals are not only a carbon source for beneficial bacteria- they're also a sort of biological filtration "substrate" for them to colonize on. Again, speculative, and needing some more rigorous scientific investigation to verify one way or another, but it's been my "working hypothesis" for several years.

In my opinion, once they get through the initial startup phase, blackwater/botanical-style systems seem to run incredibly smoothly and in a very stable manner. If you adhere to a regular, yet simple maintenance schedule, obey the long-established common-sense "rules" of aquarium husbandry, and don't go crazy with radical overstocking or trying to speed up things too much by dumping tons of botanicals into your established, stable tank in a brief span of time, these systems run almost predictably, IMHO.

And speaking of "maintenance"-  I'll concede that one of the "bummers" of botanical-style aquarium keeping is that you will likely have to clean/replace prefilters, micron socks, and filter pads more frequently. Just like in Nature, as the botanicals (leaves, in particular) begin to break down, you'll see some of the material suspended in the water column from time to time, and the bits and pieces which get pulled into your filter will definitely slow down the flow over time.

The best solution, IMHO, is to simply change prefilters frequently and clean pumps/powerheads regularly as part of your weekly maintenance regimen.

Remember, you're dealing with a tank filled with decomposing botanical materials. Good overall husbandry is necessary to keep your tank stable and healthy- and that includes regular water exchanges. At the very least, you'll likely be cleaning and/or replacing pre filter media as part of your routine, and that's typically a weekly-to bi-weekly thing.

Let's talk about the most dreaded of all aquarium occurrences: The appearance of  microalgae. 

While it would be intellectually dishonest (and just plain untrue) for me to assert that blackwater/botanical aquariums aren't susceptible to algae outbreaks, it is sort of remarkable that we simply don't have massive algae issues in these types of aquarium on a regular basis. I have to admit, that I have never had one of those nightmare algal blooms in a blackwater aquarium...and although it sounds like tannins or some other "substances" in the blackwater would be the obvious "x factor", I'll tell you that I've never had an outbreak in a clearwater aquarium, either.

So, from personal standpoint, I can shout, "My blackwater tanks don't have algae issues!" On the other had, none of my other tanks have had them, either. And I'll wager that neither have many of yours, as well!

Shit. Not helpful, huh?

I read a study from the University of Georgia, which tested the idea of algae growth in blackwater streams, to determine if the limiting factor was chemical (nutrient) or light driven...and lo and behold, the study concluded that it wasn't necessarily some magic stuff in tannins and blackwater, as much as it was light limitation! 

Yes, you heard me correctly.

Light-limiting effects of the blackwater itself were discovered to inhibit algal growth in coastal plain streams. As light penetrates the water, high DOC concentrations and suspended solids can scatter and absorb light, impacting algal growth significantly. 

Okay, sounds like a bummer if you want to believe blackwater is "magic", but the study also concluded that blackwater systems were somewhat nutrient-limited, which also affected the growth of algae- although this was not concluded to be the primary factor which inhibited algae growth. In fact, another study I perused about the Rio Negro concluded that it was found that there is a relatively small difference in "respiration rates" between "whitewater" and "blackwater" rivers, and that the presumption that blackwater systems are more "sterile" is sort of overstated.

Interestingly, the study also concluded that higher incidence of algal growth occurred in areas in Amazonia where water movement was minimal, or even stagnant, suggesting that, all things being equal, light limitation and water movement are possibly more significant than just higher nutrient concentrations alone!

And that makes sense, if you consider the long-held belief within the aquarium hobby that most plants don't do well in blackwater aquariums "because they don't get enough light!"

Yikes! 

So the long-held aquarium attitude about blackwater having some algal-inhibiting properties is really based on the fact that it's...darker? I mean, every blackwater tank I have ever owned does have some algae present. Although, being a reef guy at heart, every aquarium I own has good water movement. I know that in leaf-litter-dominated aquariums, which I love, I still keep a good amount of flow going.

This is interesting, because you'd think a tank dominated by decomposing leaf litter would be a freaking "algae farm", right? And yet, I've experienced no more occurrence of algae in the leaf litter tanks than I have in other setups. On the other hand, regardless of what type of system I work with, I'm fanatical about husbandry and nutrient control/export...obviously, another key factor.

Interesting stuff, huh? And since a lot of blackwater/botanical-style tanks are hardscape, with little or no plants, the lighting we are employing is strictly aesthetic, right? So, you're not hitting a tank with decomposing pods and no plants with 14 hours of full spectrum light...Personally, I use LED, and I keep my intensity levels very low (as low as 15% on the low end to 20%-25% on the higher end). Aesthetics.

Well, that certainly can be part of the reason why this tank magically has essentially little to no nuisance algae, huh? We pin both the praise and the blame for algae on the wrong suspects, I think! 

Man, this deserves more study...a lot of it.

Let's think about algae in the aquarium to begin with...No, not the boring old "This is how algae problems happen in our aquariums..."  bullshit lecture that you've read on every website known to man since the internet sprung to life. You can find that stuff everywhere. Rather, let's think about how we, as a group, mentally are opposed to the stuff in our tanks.

I mean, yeah, I know of no one that really enjoys a tank smothered in algae. It looks like shit, and is a "trophy" for incompetence, in the eyes of most aquarists. In fact, I remember reading once that more people quite the aquarium hobby over algae problems than almost anything else.

Yuck!

Well, sure- algae problems caused by obvious lapses in care or attention to normal maintenance, like overfeeding, lack of water changes, gross overstocking, etc. are signs of...incompetence. The occasional algae outbreaks that many hobbyists suffer through have all sorts of other potential causes, and can often be traced to a combination of small things that went unchecked, and are typically controlled in a relatively short amount of time once the causative factors are identified.

Yet, as a group, us hobbyists freak out about algae in our tanks. I can show you a hundred pics of algae and biofilm covered logs in the Amazon and the Rio Negro and say, "See it happens here too! Natural!" and the typical hobbyist will still be rendered speechless with horror at the thought of the shit appearing in her tank!

And I can't even tell you what it would do to one of those "natural aquascaping" contest freaks or judges! People might die. You could be charged as an accessory to murder! Seriously.

So, not everyone gets it. Just like brown water.

Algae is the foundation of life, blah, blah, blah. Yet, it's also the foundation for a "cottage industry" of devices, chemicals, and treatment regimens designed to eradicate it. 

Regardless of what approach we take, natural processes that have evolved over the eons will continue to occur in your aquarium. You can fight them, attempt to stave them off with elaborate "countermeasures" and labor...or you can embrace them and learn how to moderate and live with them via understanding the processes by which they appear.

And the algae?

It'll always be there. It's just a matter of how "prominent" we allow it to be.

Back to the water exchanges, and what you should/could do during these sessions.

During my water exchanges, I'm merely siphoning water from down low in the water column. I typically do not remove the broken-down leaf and botanical material, unless it's becoming a bit of a nuisance, blowing into places I don't want it.  I don't remove leaves and botanicals as they break down. I'm a sort of "leave 'em alone as they decompose" kind of guy.

And I'm not going to go into all the nuances of replacement water preparation, etc. You have your ways and they work for you. It's not really "rocket science" or anything, but everyone has their own techniques. The one "constant" is to perform regular water exchanges in your botanical-style aquariums. Just do them.

Like almost any aquarium, botanical-style blackwater/brackish aquariums require attention, management, and maintenance. Water exchanges are important, like they are in any aquarium, providing the same benefits. Water testing is important, particularly in situations where you're starting out with soft, acidic water, as the impact of botanicals is far more significant in this environment. 

 For many hobbyists, water testing is a periodic thing, done on an "as I feel it" basis. Personally, I think the benefits of a more regular testing schedule yields a lot of good benefits for us.

Your testing regimen should include things like pH, TDS, alkalinity, and if you're so inclined, nitrate and phosphate. Logging this information over time will give us all some good data upon which to develop our expectations and "best practices" for water quality management. It's important for the hobby overall to document as much information as possible about how our botanical-style/blackwater aquariums establish and operate. This gives the widest variety of hobbyists the most reasonable set of expectations about these systems.

Remember, it isn't just about a new aesthetic approach. It's about a more holistic natural approach and methodology.

Algae, and the fears which accompany it, are not entirely unfamiliar to us. However, I think that if we take a more "holistic" mindset about it, we'll be in a batter position to deal with it.

So, before you siphon out that algae patch, pull that group of weeds, or  blast that Aiptaisa anemone with kalkwasser (for you reefers out there), pause for a second to consider why and how the "offending" life form came to be in that location.

And reflect upon how we can benefit by designing our aquariums to provide the optimum environment for each and every fish and plant that we treasure to grow and thrive. To give them every opportunity to do so is our challenge, and our obligation.

Stay patient. Stay diligent. Stay creative. Stay proactive. Stay consistent...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

First things first.

A bunch of you had asked me further about the idea I brought up recently in our piece on Kuhli loaches, about pre-stocking" an aquarium with food for your fishes before you add them. You wanted more specifics.

Okay, cool. Happy to accommodate. Of course, I need you to do a little exercise, first:

You're a fish.

Seriously. Make yourself a fish...for a second. (I think I'd be a Black Ghost Knife, FYI. What, you thought I'd be a Cardinal Tetra or something? Really? Sheesh!)

Would you like to move into a house which didn’t have a refrigerator full of food?  I wouldn’t, for sure. Unlike humans, fishes seem to have not lost their "genetic programming" for grazing and hunting for food. Let’s face it—most of the waking hours of aquatic animals are devoted to acquiring food and reproducing. They need to have some food sources available to "hunt and graze" for.

That’s reality.

So why not help accommodate our your animals’ needs by supplementing their prepared diet with some “pre-stocked” natural foods in their new home? You know, slow down, get things "going" a bit, and then add the fishes?

I’m not talking about tossing in a few frozen brine shrimp hours before the first fishes go in the tank—I’m talking about a deliberate, systematic attempt to cultivate some living food sources within the system before a fish ever hits the water! Imagine a “new” system offering numerous foraging opportunities for it’s new inhabitants!

in our world, that might mean allowing some breakdown of the botanicals, or time for wood or other botanicals to recruit some biofilms, fungi- even turf algae on their surfaces before adding the fishes to the aquarium. 

“Scott. You’re being impractical here! It could take months to accomplish this. I’ve just spent tons of money and time setting up this tank and you want me to deliberately keep this tank devoid of fishes while the biofilms form and Daphnia reproduce?”

Yes. Seriously.

 I am a bit crazy. I’ll give you that. 

Yet, with my last few systems, this is exactly what I did. 

Why?

Well, for one thing, it creates a habitat for sighs which is uniquely suited to their needs in a different way.

Think abut the way most fishes live. They spend a large part of their existence foraging for food. Even in the cozy, comfortable confines of the aquarium.

So, why not create conditions for them which help accommodate this instinctive behavior, and provide opportunities for supplemental (or primary!) nutrition to be available to them by foraging.

Now, I have no illusions about this idea of "pre-stocking" being a bit challenging to execute.

I’m no genius, trust me. I don’t have half the skills many of you do but I have succeeded with many delicate “hard-to-feed” fishes over my hobby “career.” 

Any "secret" to this?

None at all.  I'm simply really fucking patient.

Success in this arena  is simply a result of deploying..."radical patience."  The practice of just moving really slowly and carefully when adding fishes to new tanks. 

A really simple concept.

I mean, to some extent, we already deploy this practice with our blackwater/brackish, botanical-style tanks, right? The very process of creating a botanical-style aquarium lends itself to this "on board supplemental food production" concept. A sort of "food web" that's pretty analogous to those found in Nature, right?

And one of the most important functions of many botanically-influenced wild habitats is the support of food webs. As we've discussed before in this blog, the leaf litter zones in tropical waters are home to a remarkable diversity of life, ranging from microbial to fungal, as well as crustaceans and insects...oh, and fishes, too!  These life forms are the basis of complex and dynamic food webs, which are one key to the productivity of these habitats.

You can do this. You can foster such a "food web"- or the basis for one- in your aquarium!

Wait a minimum of three weeks—and even up to a month or two if you can stand it, and you will have a surprisingly large population of micro and macro fauna upon which your fishes can forage between feedings.

Having a “pre-stocked” system helps reduce a considerable amount of stress for new inhabitants, particularly for wild fishes, or fishes that have reputations as “delicate” feeders.

And think about it for a second.

This is really a natural analog of sorts. Fishes that live in inundated forest floors (yeah, the igapo again!) return to these areas to "follow the food" once they flood. In fact, other than the physical flooding itself, this pursuit of food sources is the key factor in the migration of fishes into these habitats.

In the aquarium, it's not all that different. Our systems are built on the process of decomposition and fostering microbial growth. It's a foundation of the botanical-style aquarium approach. Far different than the "typical" approach to starting an aquarium, which is really more reliant on filtration, external food inputs (from us!), and the execution of consistent maintenance to get it through the "startup" period, when a typical system is almost "sterile" compared to our botanical-style ones.

And the "waiting period" isn't all that long.

It just takes a few weeks, really. You’ll see fungal growth. You'll see some breakdown of the botanicals brought on by bacterial action or the feeding habits of small crustaceans and fungi. If you "pre-stock", you might even see the emergence of a significant  population of copepods, amphipods, and other creatures crawling about, free from fishy predators, foraging on algae and detritus, and happily reproducing in your tank.

We kind of know this already, though- right?

This is really analogous to the tried-and-true practice of cultivating some turf algae on rocks either in or from outside your tank before adding herbivorous, grazing fishes, to give them some "grazing material." 

Radical patience yields impressive results.

I realize that it takes a certain patience- and a certain leap of faith-to do this. I’ve been doing it for a while and I can tell you it works.

If you like delicate or difficult-to-feed fishes, or even if you simply want to try something a bit different "just because", it’s a technique that could help you succeed where you might have failed in the past with some species.

The point of this practice is pretty simple. Embrassingly so, actually: To help develop—or I should say—to encourage the development and accumulation of some supplemental natural food sources in the system before they are quickly devastated by your fishes.

It's kind of the "refugium" concept yet again.

And it's not all decomposing leaves and twigs and stuff that helps accomplish this- in Nature and I the aquaruum.

One of the important food resources in natural aquatic systems are what are known as macrophytes- aquatic plants which grow in and around the water, emerged, submerged, floating, etc. Not only do macrophytes contribute to the physical structure and spatial organization of the water bodies they inhabit, they are primary contributors to the overall biological stability of the habitat, conditioning the physical parameters of the water.

Of course, anyone who keeps a planted aquarium could attest to that, right? 

One of the interesting things about macrophytes is that, although there are a lot of fishes which feed directlyupon them, in this context, the plants themselves are perhaps most valuable as a microhabitat for algae, zooplankton, and other organisms which fishes feed on. Small aquatic crustaceans seek out the shelter of plants for both the food resources they provide (i.e.; zooplankton, diatoms) and for protection from predators (yeah, the fishes!).

Of course, leaves are a huge and important component in the construction of a food web.

Decomposing leaves will not only provide material for the fishes to feed on and among, they will provide a natural "shelter" for them as well, potentially eliminating or reducing stresses.

And the possible benefits to fish fry are interesting Gand important, IMHO.

In Nature, many fry which do not receive parental care tend to hide in the leaves or other biocover in their environment, and providing such natural conditions will certainly accommodate this behavior.

Decomposing leaves can stimulate a certain amount of microbial growth, with infusoria and even forms of bacteria becoming potential food sources for fry. I've read a few studies where phototrophic bacteria were added to the diet of larval fishes, producing measurably higher growth rates. Now, I'm not suggesting that your fry will gorge on beneficial bacteria "cultured" in situ in your blackwater nursery and grow exponentially faster.

However, I am suggesting that it might provide some beneficial supplemental nutrition at no cost to you!

I've experimented with the idea of "onboard food culturing" in several aquariums systems over the past few years, which were stocked heavily with leaves, twigs, and other botanical materials for the sole purpose of "culturing" (maybe a better term is "recruiting) biofilms, small crustaceans, etc. via decomposition. I have kept a few species of small characins in these systems with no supplemental feeding whatsoever and have seen these guys as fat and happy as any I have kept.

And it's the same with that beloved aquarium "catch all" of infusoria we just talked about...These organisms are likely to arise whenever plant matter decomposes in water, and in an aquarium with significant leaves and such, there is likely a higher population density  of these ubiquitous organisms available to the young fishes, right?

Now, I'm not fooling myself into believing that a large bed of decomposing leaves and botanicals in your aquarium will satisfy the total nutritional needs of a batch of characins, but it might provide the support for some supplemental feeding! On the other hand, I've been playing with this recently in my "varzea" setup, stocked with a rich "compost" of soil and decomposing leaves, rearing the annual killifish Notholebias minimuswith great success.

It's essentially an "evolved" version of the "jungle tanks" I reared killies in when I was a teen. A different sort of look- and function! The so-called "permanent setup"- in which the adults and fry typically co-exist, with the fry finding food amongst the natural substrate and other materials present I the tank. Or, of course, you could remove the parents after breeding- the choice is yours.

So, what would some candidate organisms be for "pre-stocking" a botanical-style aquarium?

How about starting with (okay, sounding a bit commercial, I know, but...) the versatile Purple Non Sulphur Bacteria (PNSB), Rhodopseudomonas palustris- the species which forms our product, "Culture." PNSB are useful for their ability to carry out a particularly unusual mode of metabolism: "anaerobic photoheterotrophy."

In this process, they consume organic wastes while inhabiting moderately illuminated and poorly oxygenated microhabitats (patches of detritus, leaf litter beds, shallow depths of substrate, deeper pores of expanded clay media, etc.). In addition to helping to maintain an ecologically stable microhabitat, "Culture" provides a nutritious live food source for zooplankton as well as soil mesofauna.

Yeah, these guys form the "foundation" of your food chain!

Next, perhaps some "starter cultures" of organisms like Paramecium, Euglena, etc. You know, "infusoria" from the old school aquarium literature. And then, small crustaceans like Daphnia, and copepods of various types.

Pure cultures of all of these organisms are available online from various biological supply houses. They're a fantastic source of biodiversity for your aquarium! 

Of course, the more daring among you may want to introduce various worms, like "Black Worms" or Tubifex worms, if you can find clean cultures of them. For that matter, even "blood worms", which are actually the larval phase of the midge.

Some organisms, such as nematodes and chironomids ("Bloodworms!") will dig into the leaf structures and feed on the tissues themselves, as well as the fungi and bacteria found in and among them. These organisms, in turn, become part of the diet for many fishes.

In the aquarium, just like in Nature, some organisms, such as nematodes and chironomids ( those damn Bloodworms again!) will dig into the leaf structures and feed on the tissues themselves, as well as the fungi and bacteria found in and among them.

These organisms, in turn, become part of the diet for many fishes.

Food Web.

And the resulting detritus (here we go again!) produced by the "processed" and decomposing plant matter is considered by many aquatic ecologists to be an extremely significant food source for many fishes, especially in areas such as Amazonia and Southeast Asia, where the detritus is considered an essential factor in the food webs of these habitats.

It performs the same function in an aquarium- if we allow it to.

And of course, if you observe the behavior of many of your fishes in the aquarium, such as characins, cyprinids, Loricariids, and others, you'll see that, in between feedings, they'll spend an awful lot of time picking at "stuff" on the bottom of the tank. In a botanical style aquarium, this is a pretty common occurrence, and I believe an important benefit of this type of system. 

When you start seeing your fishes "graze" casually on the materials that pop up on your driftwood and botanicals, you start realizing that, although it might not look like the aesthetics we have had in mind in years past, it is a beautiful thing to our fishes!

 You can do this.

And, as a lover of the botanical-style aquarium, you're at the forefront of the art and science of creating functional food webs within the aquarium. And it all starts with patience.

First thing first.

Stay patient. Stay studious. Stay excited. Stay curious. Stay bold...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Edits, iterations, and pivots.

One of the best things about the aquarium hobby is that there is an endless amount of inspiration provided by Nature, which generates a seemingly endless amount of ideas.

Like so many of you, I love thinking about ideas for unusual concept aquariums. I like to look at things a bit differently. Tannin was founded based upon looking at things a bit differently; helping hobbyists re-think the way Nature really looks, and to promote the creation of aquariums which replicate not only the look- but the function- of natural aquatic habitats.

This philosophy has influenced so much of what we do here.  I think I have a strong sense of  the kind of aesthetic that I find attractive, like many of you do. I tend to sort of "stay in my lane", so to speak. I try to stay true to my interpretations of Nature and this is reflected in my aquarium executions. And I try to take my ideas to fruition whenever possible.

However, occasionally- I get these bouts of what I call “aquatic indecisiveness.”

Do you get what I mean by that? I've touched on this before, but it's really become a predictable habit with me. Let me explain. It’s like, I’ll have this awesome plan for stocking the aquarium I've been working on for a while; I get this vision of executing on the plan and ending up with an aquarium that looks just like I imagined it would, aquascaped exactly how I envisioned, stocked exactly how I envisioned, and running just like I expected.

So, I tediously conceive, design, build, and equip the system. When I finish setting it up, the concept that I spent countless sleepless nights conceiving comes together. Then…I stare at the promising, yet unstocked new tank and just…edit.

Huh? 

Yeah, you heard me, I’ll “edit.”, gradually dissecting my beautiful concept and morphing it into something else.

Moving this. Re-positioining that. Taking out an element, adding something. Now, a lot of people will call this process “evolution”, or view it as a necessary stage in the development of an aquarium. I call it “A.D.D.” or something! Not sure.  It's like  all of the sudden, I’ll see an article about "ephemeral floating leaf litter beds" or an underwater video of an Amazonian igarape, and my carefully conceived African River biotope goes straight out the damn window.

Off we go... into a totally different direction!

I think I’m what I like to classify as a “Perpetual Editor” -type of aquarium personality. At least, in terms of my ideas.

It's a bit odd that I edit ideas so quickly, because, as you know- I'm obsessed with the process...I have huge patience in establishing my aquariums and leaving them to evolve largely unmolested. It's really at the initial execution or ideation phase where I get detoured.

Now, don’t get me wrong. My core beliefs about aquarium keeping are typically unchanging..well, they evolve, as you've seen on these pages, based on experience-like everyone else. And, like you, I am always open to suggestions to do something better. Sometimes, this is a good thing. I mean, if your idea was to develop a Knifefish community in a 50-gallon tank, and you "pivoted" to a 700-gallon tank after running it by some friends, that’s a very good thing!

“Coming to your senses” is what it’s called.

However, my changes are often more subtle: For example, I was planning on stocking an all-South-American characin system, but ended up creating a Rasbora-dominated biotope instead.

You know, that kind of thing...

Totally different part of the world and all that.

Or I'll tell myself something like, "I don’t want any cichlids in this tank!" That is, until I run across a source for amazing wild Dicrossus…You know, that kind of chance meeting that throws the whole plan into disarray! Sounds oddly romantic and exciting, only we’re talking about an aquarium, not meeting the girl or guy of your dreams, ya know?

Yeah, it’s a burden, this endless "susceptibility to suggestion", right?

Perhaps- maybe- it’s an advantage, because it gives me the chance to correct things that would otherwise be disastrous, shortsighted, or just..stupid. Or, perhaps it has stifled some brilliant work. I’d like to think not, but you never know. I greatly admire those of you who can create- and stick- to a plan for your tanks. Now, don't get me wrong, there ARE many times when I've created a plan, stuck to it, and was richly rewarded for my effort.

I can think of a couple of examples from fish keeping history where hobbyists have executed exactly what they intended- with amazing results and surprisingly influential impact on the hobby.

Look, I’m not saying that you need to have architectural renderings, a monumental checklist, and never deviate for one second in order to have success. Rather, I’m suggesting that conceiving- and sticking to- a plan for your aquarium is never a bad thing. 

Okay, I'm probably doing this as form of "reassurance", huh?

Yeah, like I can take my own suggestion so well, right?

It can get really crazy. During one particularly frenetic period of time in 2017, I re-did the same tank three different times in a span of about 3 months. 

It can get a little bit crazy, I know.

On the other hand, being a “Perpetual Editor” archetype of fish keeper also has his/her advantages. mainly, the ability to modify a plan as he/she goes if he sees a better way.

Almost categorically, the “Perpetual Editor” has a looser, more flexible approach to  aquarium planning, construction, and management, and is perhaps more in tune with the latest and greatest trends, techniques, and philosophies of the aquarium game. (and of course, more susceptible to being influenced by a lot of stuff!) Now, I hate "trends", personally. However, I do find myself influenced strongly by new research I conduct on various wild habitats.

Yeah, I personally hate chasing trends. Really. 

There is a sort of “sub-category” in the “Perpetual Editor” classification…well, actually, two: The “Trend Jumper”, who, as the name implies, switches direction at the drop of a hat in order to capitalize on the latest trends, fads, or ideas.  I mean. good for them if they want to replicate  the latest and greatest trends they see on Instagram or wherever. Respect.

The other, what I call an “Active Listener”, will make changes based on discourse with other hobbyists, who share ways to do the thing that you’re trying to do in a different, or perhaps, better, more efficient manner. 

A good thing, I believe!

One thing about being a “Perpetual Editor” is that you are constantly availing yourself to the latest information, and, in the case of the “Active Listener”, probably having great dialogue with other hobbyists who perhaps have more- or different- experience doing what you’re thinking of doing.

The online world and social media have enabled the “Active Listener” to develop his or her idea to the ultimate degree. Although, the "danger" of being an “Active Listener” is that you can easily “lose control” of your plan by listening to every critique, suggestion, and opinion out there.  

And the "trend jumpers?" Well, e-commerce has completely enabled these people, right? You can switch gears in an instant. Regardless of your aquarium-keeping philosophy, a certain degree of independence and individuality is a key requirement to be happy, I think.



In a way, being a “Perpetual Editor” is not really a bad thing.

I mean, you’re always aware of what’s going on in your tank, you’re constantly thinking of improvements and changes, you're totally aware of the “Latest and Greatest” in the hobby, and you are “nimble”- able to change directions "on a dime", as they say. The key, in my opinion, is to stay consistent with your management philosophy. Like, just because the new tank is getting that patina of biofilm, it's not the time to tear out everything and start over. That's not editing...that's interfering!

Yeah, understanding when NOT to "edit" and why is as important as understanding when to edit!

So, don’t despair, sufferers of ADD (Which, IMHO is pretty much everyone in the aquarium keeping world, IMHO...a thesis I'll have to revisit at some point), it helps you be a better, more “agile” hobbyist.

And the great 'scapers, like Jeff Senske of Aquarium Design Group, listen to what's in their heart- pull inspiration from the world around them- and execute based on their instinct and aesthetic. They approach it with an almost yoga-esque calm and vision that comes from being totally in touch with their feelings. It's amazing to see the work that comes from guys like Jeff, Johnny Ciotti, Luis Navarro, George Farmer, Oliver Knott..

They do it with real "soul."

So being a "perpetual editor" is an interesting "burden"- or blessing, depending upon how you look at it. And I've just looked at it from the tank design and hobby perspective!

I’d like to hear from those of you out there who “suffer” from this double-edged sword, and how it impacts your hobby experience.

Are you a “Perpetual Editor?”

Ponder that…And until next time…

Stay creative. Stay inspired. Stay true to yourself. Stay open-minded. Stay bold. Stay on track...if you can!

And Stay Wet.

Scott Fellman

Tannin Aquatics 

The fishes of my childhood...The "Kuhli Loach.."

As a kid growing up in the aquarium hobby, I remember how incredible it was to see the enormous array of fishes that were available.

If I had to select one fish that pretty much got me into the hobby, believe it or not, it'd have to be the "Kuhli Loach", Pangio kuhlii.

It was exotic, fun, and everything I felt a tropical fish should be.

And quite frankly, it was the first example of a fish that I collected which I hadn't a damn clue how to really keep it correctly. By some miracle, many my Kuhlii seemed to survive despite my ineptitude. In more recent years, I've come to really understand this fish more by studying not only the fish and it's ecological adaptations, but studying the natural environment from which it comes, as well. 

Now, in case you've truly been living under a rock and don't know about this fish, it's a slender, almost "eel-like" fish, with largely nocturnal habits and endearing behaviors. They top out at around 4" (10 cm), so they're well-suited for modest-sized aquariums.

Although they look superficially like eels, they are most definitely not. Eels have  fused pelvic, anal, and caudal fins. Kuhli loaches have distinct pelvic fins and their dorsal, caudal and anal fins are distinct and separate.

(Image by Robert Mollick, used under CC BY-SA 3.)

We tend to call them "scaleless" fishes, because they have really small, widely-spaced scales, giving them the appearance of being scaleless. That being said, they are a bit sensitive to medications and such, much in the way truly scaleless fishes are, so use caution when exposing them to medications or salt, etc.

This is also another reason why you should keep them in aquariums with softer substrates, like sand, or mixed botanical substrates. Not only will this help prevent injuries which may lead to infection, it more accurately replicates the substrates found in the wild habitats from which they come- the environments which I believe we should be replicating when we keep these unique fish.

(Cool fish. Not cool substrate choice.)

Of course, like many fishes, this species suffered over the years from a lot of taxonomic reshuffling, and it's been known by the pseudonyms, Acanthophthalmus kuhlii and Cobitis kuhlii...A real mess! The species name is an homage to zoologist Heinrich Kuhl (an interesting character who died way too young..One could only imagine the discoveries he could have made had he lived longer...).

Oh, and there are a bunch of very similar-appearing species to simply add to the confusion. Pangio kuhlii may actually represent a "species complex" and commonly used "synonyms" include Acanthophthalmus kuhli, A. semicinctus, and Pangio semicincta.

Confusion.

And, hobbyists being hobbyists, we've lazily referred to this fish as the "Coolie" Loach for generations, because...well..because we're lazy, and because, apparently, it's easier to spell "coolie" than it is to spell "kuhlii" or "kuhli" for some reason...😆

The meaning of the genus Acanthopthalmus is 'thorn' or 'prickle-eye', after a spine beneath each one of the fish's eyes, a strong homage to the anatomical protection afforded them for their habit of burrowing into soft substrates, like sand, mud, and leaf litter.

That sounds good!

Who in our world doesn't love a fish morphologically adapted to burrowing into leaf litter?🤓 Now, the burrowing habits of this fish don't endear them to everyone, of course. Planted tank people are anything but excited about the roots of their precious plant specimens being exposed! And these guys tend to be rather nocturnal in nature, so you're likely to only catch glimpses of them most days. You often see them comically and endearingly  buried in the substrates, with only their heads poking up. 

Oh, and they're a bitch to net. Don't believe me- ask anyone who's ever worked at the LFS who's job it was to catch the wiggly little bastards! 

Kuhlis are social, gregarious fishes. Shoaling fishes, more specifically. They categorically are best kept in group. I wouldn't even consider keeping this fish if you don't have the ability to accommodate at least 4-5 of 'em- or, more beneficially, up to a dozen or more. Gregarious, yup!

(Image by Marrabbio2. Used under CC BY-SA 3.0)

However, they are not fishes that you're likely to see out at all hours of the day in a brightly-illuminated aquarium, dancing in the current or rushing to the front glass in search of food for all to see. This reclusive behavior makes them a fish that really, truly deserves an aquarium of their own. If sufficient food doesn't reach the bottom where they dwell, or if food sources aren't available within the substrate itself, these fishes can easily starve to death. 

You may occasionally find one in a filter intake or overflow, waiting for you to rescue it. This is a typical occurrence with these guys, and a very sure indicator that some heavy-duty "loach partying" was going on in the tank the night before! Checking those "weird spaces" each morning is just part of the daily ritual when you keep these guys.

Oh, while we're talking about the Kuhli's morphology and how it takes advantage of it,  let's take a second to whack us hobbyists upside the head one more time! For some bizarre reason, this fish is popularly relegated to the "role" of "scavenger."  Like, WTF? Does EVERY fish with reclusive nature, bottom-dwelling habits, and nocturnal preferences have to be branded a "scavenger?"

(NOT a scavenger. However, it lives on the bottom of the tank...😂)

In the wild, they tend to eat small crustaceans, insect larvae, and sometimes fish eggs....A similar diet to many other fishes that we don't anoint as "scavengers", right? Like, Tetras..I mean, are Cardinal Tetras "scavengers?" Damn, what the hell is wrong with us? Now, granted, they'll often ingest a bit of substrate to sift through for crustaceans and such..but this benthic feeding behavior does not mean that they are "scavengers." 

Stop thinking of them as such. Just don't purchase these fishes with the intent of utilizing them to "keep the tank clean." That's not the fishes' responsibility It's yours. And, YOU have a damn siphon hose for that! Don't like that responsibility? Cool. Just take up collecting sneakers or something. 🤬

"Okay, deep breath, Fellman." Early morning rant over!

Of course, I'm fascinated by this fish, but I'm even more fascinated by its environment. Of course, the habitats from which our fishes come from always seem to dictate their morphology, right? So one can learn a lot about a fish by learning more about its habitat!

Geographically, the fish has been collected from a broad range of locales, as wide apart as Indonesia and Malaysia. Oh, and Thailand, In fact, I even stumbled on a work entitled  "Peat swamp fishes of Thailand." from 2002 which referenced it's occurrences there.

The environments that this fish is found in are many and varied. Fishbase references "hill streams to lowland forest canals and peats." Of course, the "peats" part fascinates me. A reference to the peat swamp forests that we've discussed before...an almost irresistible subject for a proper botanical-style aquarium!

And, as we all know, the substrates in many of our fishes' habitats directly influence the chemical environment. Of course, the habitat of the Kuhli is no exception. My research revealed that the fish is found in water with pH ranging from 5.5 - 6.5. 

It's also indicated that it comes from Shallow, sandy streams with fine cobbled rocks and a few branches and leaves.

Seems like there are always leaves, huh?

I think the real fun with these fishes can be had when we make anattemtp to replicate as many aspects of their natural habitat as possible- specifically, the substrates. 

In peat swamps, the peat layers may be well in excess of  3 feet (1m) deep. The floodplain forests are found along rivers, streams, coasts, and lakes. The seasonal flooding inundating the forests for short periods leads to an influx of sediment and mineral enrichment during high water periods. 

These soils are best replicated by using "non-traditional" substrates, like...coconut-based materials, finely-crushed botanicals, mud, sediments, etc...

And I also feel very strongly that the Kuhli, like many fishes with benthic lifestyles, can benefit from being kept in an aquarium designed and configured to provide feeding opportunities within the system itself, to supplement any foods that we're offering.

Many fishes, like Headstanders, characins, and others, simply consume tiny crustaceans as part of their sediment feeding activity. Now that we're more likely to set up aquariums with fine, silty sediments stocked with tons of little copepods and worms and such, these experiments may yield very interesting results!

It is absolutely possible to create a real "active substrate", filled with these creatures, and to be able to "pre-stock' it with cultures of small life forms prior to the introduction of fish! And of course, there are ways to replenish the population of these creatures (and even the substrate itself) periodically, resulting in extremely productive systems, too!

An interesting experiment to think about, huh? Even more interesting to actually execute. Such a system, with a heavy "substrate-centric" focus can be successfully managed long-term- resulting in a terrific environment for Khulis and others.

And of course, the whole idea of a rich, sediment-sand-and-soil substrate enriched with botanical materials is completely in line with the "best practices" we've developed as a community to create dynamic, botanical-style aquariums. In our case, not only will there be an abundance of trace elements and essential plant nutrients be present in such a substrate, there will be the addition of tannins and humic substances which provide many known benefits for fishes as well.

The best of both worlds, I think!

Now, sure, this tank will probably have some suspended material in it at all times. The water may not be 100% crystal clear, because of the Kuhli's benthic habits. It goes with the territory, and it's simply something we need to understand and appreciate when going the more natural route.

These dynamic habitats are not difficult to replicate in the aquarium. We need to understand that they play a functional and aesthetic role in the overall aquarium, as we've touched on many times here. Realizing that placing leaves and botanical materials on the bottom of the aquarium is not simply making an aesthetic statement. Rather, it's an homage to the function of the dynamic habitats we love so much.

I am 100% certain that this is the key to keeping fishes like our friends the Kuhli loach extremely happy for extended periods of time.

To me, that's the most amazing part about keeping the fishes of my childhood: Merging the excitement and fascination they bring with the art and science of providing as accurate a representation of their natural habitat as possible. 

Stay creative. Stay studious. Stay persistent. Stay observant...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Permission

Remember when you were back in elementary school, and your class would take a "field trip" to a museum or some place like that, and you had to get a "permission slip" signed by your mom or dad? It was like the "golden ticket!" A license to voyage beyond the normal confines of the classroom, or even the playground! I remember how good it felt; how empowering- to have that signed permission slip and to be able to go on that excursion to some interesting and exciting place.

I think we all can relate to that, right?

Flash forward a few decades, and it seems like many of us in the aquarium hobby are still looking for that "permission slip"- albeit a metaphorical one- to venture outside of the boundaries of what is considered "acceptable" or "normal" aquarium practice. I routinely receive emails from fellow hobbyists asking me if it's okay to attempt certain things in a botanical-style aquarium. It's interesting and a bit funny that people ask me these questions- as if I'm some "authority figure" who needs to "sign off" on everyone's botanical-style aquarium experiments.

I'm not, of course. However, I am honored to be considered as a source of advice for this kind of stuff. Like many of you, I've played with this stuff for many years, and I've had a lot of experiences-mostly good, but some not-so-good- with these types of experiments. And it's not like me or anyone else has to give you "permission" to go for it.

On the other hand, I'm proud that both myself and many members of our community are boldly trying some new ideas that certainly fly in the face of "conventional aquarium wisdom" and practice, and have yielded interesting benefits for our fishes. And, humans being humans, we like the "approval" of our peers to try stuff previously viewed as "taboo."

I thought it might be fun to look at a few of the things which we as hobbyists previously felt a bit scared to attempt, but now, thanks to the hard work of our community, feel that we collectively now have "permission" to proceed with! Let's get right to 'em:

Fungal growths and biofilms are okay to have in your aquarium. Yeah, the idea of seeing these stringy, gooey-looking growths on our leaves and botanicals and wood can certainly cause concern for many hobbyists. The rapidity with which it grows and proliferates can be downright frightening for the uninformed hobbyist. A century of aquarium hobby practice and thought leadership by experts has told us this is really BAD! Get it out- like, immediately.

Yet, this is a mandate that we have followed dutifully for generations without thinking about the upsides to this stuff.

We have to look at how these growths occur and benefit aquatic habitats in Nature.

Of course, the process ultimately leads to physical breakdown and/or fragmentation of the leaves and botanicals into smaller "pieces", which possess larger amounts of surface area for microbial attachment.  Extensive ecological studies done by scientists specifically in regard to leaf litter have yielded a lot of information about this process.

Now, sure, there could be a downside to having all of this growth in your tank...and it has to do both with the prolific nature of fungi and the impatience of us as hobbyists. We need to consider the fact fungal colonization facilitates the access of invertebrates to the energy trapped in deciduous leaves and other botanical materials found in the aquatic environment. Bacteria and fungi that decompose decaying plant material in turn consume dissolved oxygen for respiration during the process.

This is why adding too much botanical material too rapidly to an aquarium can create problems for the fishes! A rapid decrease in dissolved oxygen in a small body of water can be disastrous; or, at the very least, leave fishes gasping at the surface! And of course, that's why we tell you to deploy massive patience and to go slowly when adding botanicals to an established aquarium...

Of course, that's the worst case scenario- precipitated by us as impatient hobbyists adding too much stuff to an established aquarium too quickly. It's common sense. However, when we employ patience and allow fungal growths and biofilms to grow and proliferate, we can benefit our aquariums in ways previous generations of aquarists haven't considered.

These growths serve as a "medium" upon which other food sources accumulate and reproduce.

In the wild tropical leaf-litter-fueled ecosystems we love so much, creatures like hydracarines (mites), insects, like chironomids (hello, blood worms!), and copepods, like Daphnia, are the dominant fauna that fishes tend to feed on.  Thes organisms feed directly on biofilms, fungal growths, and the leaves themselves.

Gut content analysis of fishes which inhabit leaf litter habitats reveals a lot of interesting things about what our fishes consume.

For one thing, in addition to the above-referenced organisms, organic detritus, fungal growths, and "undefined plant materials" are not uncommon in the diets of all sorts of fishes.This is interesting to contemplate when we consider what to feed our fishes in aquariums, isn't it?

Again, just think about it: These life forms, both planktonic and insect, tend to feed off of the leaf litter itself, as well as fungi and bacteria present in them as they decompose...Just like the fishes that are found there. And of course, this "interconnectivity" between various levels of life forms creates the basis for a fascinating and surprisingly productive "food web."

Food webs, defined as "a system of interlocking and interdependent food chains" are fascinating constructs in Nature. The leaf litter bed is a surprisingly dynamic, and one might even say "rich" little benthic biotope, contained within the otherwise "impoverished" blackwaters which surround it. 

And, as we've discussed before on these pages, it should come as no surprise that a large and surprisingly diverse assemblage of fishes make their homes within and closely adjacent to, these litter beds. These are little "food oases" in areas otherwise relatively devoid of food.

 It works the same way in our aquariums.

Allowing botanicals and leaves to fully break down in the aquairum. As we've discussed for years here, leaving leaves and botanicals in our aquairums to fully decompose does not have a detrimental impact on water quality in otherwise well-managed systems.

Pieces of leaves and botanicals fall to the bottom of the aquairum, and form a bed of…detritus. Yes, I said detritus. In the aquarium world, we've long vilified the stuff as “a destroyer of water quality”; an impediment to successful aquariums. And the reality is that, in a well-managed aquarium, "detritus" is an essential food source for many organisms and plants. 

Like anything else in a closed system, if it's not allowed to accumulate unchecked to the point of creating a real mess in the tank, I personally believe its benefits for the animals we keep far outweigh any perceived disadvantages of having it present.

I know that uneaten food and fish poop, accumulating in a closed system can be problematic if overall husbandry issues are not attended to. I know that it can decompose, overwhelm the biological filtration capacity of the tank if left unchecked. And that can lead to a smelly, dirty-looking system with diminished water quality. I know that. You know that. In fact, pretty much everyone in the fucking hobby knows that.

That's not the issue, really, IMHO.

The "issue" is that we as a hobby have sort of heaped detritus into this "catch-all" descriptor which has an overall "bad" connotation to it. Like, anything which is allowed to break down in the tank and accumulate is bad.

I'm not buying it.

Why is this necessarily a "bad" thing?

Check out he definition of detritus: 

"detritus is dead particulate organic matter. It typically includes the bodies or fragments of dead organisms, as well as fecal material. Detritus is typically colonized by communities of microorganisms which act to decompose or remineralize the material." (Source: The Aquarium Wiki)

I mean, even in the above the definition, there is the part about being "colonized by communities of microorganisms which act to decompose or remineralize…"

Hmm...

It's being processed. Utilized. What do these microorganisms do? They eat it...They render it inert. And in the process, they contribute to the biological diversity and arguably even the stability of the system. Some of them are utilized as food by other creatures. Important in a closed system, I should think.

It's not all bad, right?

And it's fueled by stuff like decomposing leaves and botanicals.

So, yeah- I let my leaves and botanicals stay in my aquariums until they completely break down, only removing them if they become an annoyance (ie; every time a fish moves, a pile of the shit gets stirred up, or its accumulating on my driftwood, etc.)- but it never gets to that point in my tanks.

It's not an excuse for sloppy husbandry, or neglecting the removal of offensive materials. However, it IS a sort of acceptance of the fact that "stuff happens" in nature- and in aquariums- and that many of these things are simply not worth getting upset about. I mean, if you have an aquarium with brown water, and substrate dominated by decomposing leaves and softening botanicals, it shouldn't come as any surprise, right?

Decomposition is not something to freak out about. Rather, it's something to celebrate. Life, in all of its diversity and beauty, still needs a stage upon which to perform...and you're helping provide it, even with material changes taking place daily.

The real the key here is that pace- and an understanding that the materials that we add need to be added-and replaced- at a pace that makes sense for your specific system. An understanding that you'll have a front row seat to the natural processes of decomposition, transformation, decay...and accepting that they are part of the beauty of this style of aquarium, just like they are in Nature.

Mixing botanical materials into your substrate. We've been talking about the idea of "substrate enrichment" and utilizing alternative materials to create "active" botanical substrates I the aquarium for over 5 years now. We've. been doing this ourselves for a long time with nothing but good results.

One of the things that many hobbyists ponder when we contemplate creating substrates consisting of leaves, sand, and other botanical materials is the buildup of hydrogen sulfide, CO2, and other undesirable compounds within the substrate.

Well, it does make sense that if you have a large amount of decomposing material in an aquarium, that some of these compounds are going to accumulate in heavily-"active" substrates. Now, the big "bogeyman" that we all seem to zero in on in our "sum of all fears" scenarios is hydrogen sulfide, which results from bacterial breakdown of organic matter in the total absence of oxygen.

Let's think about this for a second.

In a botanical bed with materials placed on the substrate, or loosely mixed into the top layers, will it all "pack down" enough to the point where there is a complete lack of oxygen and we develop a significant amount of this reviled compound in our tanks? I think that we're more likely to see some oxygen in this layer of materials, and I can't help but speculate- and it IS just speculation- that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually be able to occur in a "deep botanical" bed.

And it's certainly possible to have denitrification without dangerous hydrogen sulfide levels. As long as even very small amounts of oxygen and nitrates can penetrate into the substrate this will not become an issue for most systems. I have yet to see a botanical-style aquarium where the material has become so "compacted" as to appear to have no circulation whatsoever within the botanical layer. Now, I base this on visual inspection of numerous tanks, and the basic chemical tests I've run on my systems under a variety of circumstances.

The understanding that substrate in the aquarium can be more than just sand or gravel- and, indeed- should be in many circumstances- is to me one of the great advances in our hobby. When we consider that almost all aquatic habitats are influences by the surrounding terrestrial environment, it's simply head-scratching to me that we haven't played with this idea for years and years I the aquarium hobby.

You can have tinted, even turbid water without it being "dirty"   In the aquarium, the hobby at large tends to see colored water, or water with some turbidity to it, and think..."dirty." 

It's head scratching to me how this came to be. And it's a HUGE "thing" when we hear criticisms and concerns from other parts of the aquarium world about our work.  There's a lot of confusion and misunderstanding at play here...and a lot of commentary from people who just don't understand this stuff all tat well.

And of course, this is where we need to separate two factors:

Turbidity (generically referred to as "cloudiness") and "color" are generally separate issues for most hobbyists, but they both seem to cause concern. Cloudiness, in particular, may be a "tip off" to some other issues in the aquarium. And, as we all know, cloudiness can usually be caused by a few factors:

1) Improperly cleaned substrate or decorative materials, such as driftwood, etc. (creating a "haze" of micro-sized dust particles, which float in the water column).

2) Bacterial blooms (typically caused by a heavy bioload in a system not capable of handling it. Ie; a new tank with a filter that is not fully established and a full compliment of livestock).

3) Algae blooms which can both cloud AND color the water (usually caused by excessive nutrients and too much light for a given system).

4) Poor husbandry, which results in heavy decomposition, and more bacterial blooms and biological waste affecting water clarity. This is, of course, a rather urgent matter to be attended to, as there are possible serious consequences to the life in your system.

And, curiously enough, the "remedy" for "cloudy" water in virtually every situation is similar: Water changes, use of chemical filtration media (activated carbon, etc.), reduced light (in the case of algal blooms), improved husbandry techniques (i.e.; better feeding practices and more frequent maintenance), and, perhaps most important- the passage of time.

There are of course, other factors that affect clarity, like fishes that dig or otherwise disturb the substrate and wood with their grazing activities, but these are not necessarily indicative of husbandry issues.

Okay, that was "Aquarium Keeping 101", actually.

Although we all seem to know this, I hear enough comments and questions about the color of the water and its relation to "cleanliness" in  natural, botanical-style blackwater systems that it warranted this seemingly "remedial" review!

Remember, just because the water in a botanical-influenced aquarium system is brownish, it doesn't mean that it's of low quality, or "dirty", as we're inclined to say. It simply means that tannins, humic acids, and other substances are leaching into the water, creating a characteristic color that some of us geeks find rather attractive. If you're still concerned, monitor the water quality...perform a nitrate test; look at the health of your animals. What's happening in there?

People ask me a lot if botanicals create "cloudy water" in their aquariums, and I have to give the responsible answer- yes. Of course they can!

If you place a large quantity of just about anything that can decompose in water, the potential for cloudy water caused by a bloom of bacteria exists. The reality is, if you don't add 3 pounds of botanicals to your 20 gallon tank, you're not likely to see such a bloom. It's about logic, common sense, and going slowly.

Remember, too, that some "turbidity" in the water, in either a "whitewater" or "blackwater" system, is natural,expected, and not indicative of a problem. In many natural settings, water is chemically perfect but not entirely "crystal clear."  I believe that a lot of what we perceive to be "normal" in aquarium keeping is based upon artificial "standards" that we've imposed on ourselves over a century of modern aquarium keeping. Everyone expects water to be as clear and colorless as air, so any deviation from this "norm" is cause for concern among many hobbyists.

In my home aquariums, and in many of the really great natural-looking blackwater aquariums I see the water is dark, almost turbid or "soupy" as one of my fellow blackwater/botanical-style aquarium geeks refers to it. You might see the faintest hint of "stuff" in the water...perhaps a bit of fines from leaves breaking down, some dislodged biofilms, pieces of leaves, etc. Just like in nature. Chemically, it has undetectable nitrate and phosphate..."clean" by aquarium standards.

Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

"Turbidity." Sounds like something we want to avoid, right? Sounds dangerous...

On the other hand, "turbidity", as it's typically defined, leaves open the possibility that it's not a negative thing:

 "...the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air..."  

What am I getting at?

Well, think about a body of water like an igapo adjacent to the Rio Negro, as pictured above in the photo by Mike Tuccinardi. This water is of course, "tinted" because of the dissolved tannins and humic substances that are present due to decaying botanical materials.  And it's also a bit "turbid" because of the fine particulate matter from these materials, too.

In summary- tinted, turbid water and high water quality are not mutually exclusive. You can have these and have excellent water quality. I know, because most of my tanks look like that, and have water quality on par with most reef systems I've kept over the years.

In the end, you don't need my "permission"- or anyone's- to try new things; to push the boundaries out into unconventional practices. The natural, botanical-style aquarium is so interesting to me because it offers enormous opportunity to execute aquariums based on the function of natural habitats- functions which, although they may look different than anything we've ever done before, may just unlock the keys to many new aquarium discoveries.

What I can promise to you in 2021 and beyond is that we will continue to provide products, ideas, and inspiration to give you the tolls you need- and hopefully, the confidence- to move forward boldly, to unlock all sorts of exciting aquarium-related things. So, you do have my permission...to have FUN!

Stay excited. Stay bold. Stay creative. Stay curious. Stay intrigued...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Endless

 There is something fascinating and enticing to me about the idea of keeping an aquarium system "going" for very long periods of time, occasionally changing things up; leaving the "operating system" largely intact, while replacing the "soft" components over time.

Example?

Let's say that you're kind of over your Southeast Asian Cryptocoryne biotope, and ready to head West to South America.

So, rather than tearing up the entire tank, removing all of the plants, the hardscape, the leaves and botanicals, and the substrate, you opt to remove say, only the plants and the driftwood/rocks from the tank; exchange a good quantity of the water.

Woooah! Crazy! You fucking rebel...

I know. I know. This isn't exactly earth-shattering. 

On the other hand, in the world of the botanical-style aquarium, the idea of leaving the substrate and leaf litter/botanical "bed" intact as you "remodel" isn't exactly a crazy one. And conceptually, it's sort of replicates what occurs in Nature, doesn't it?

Yeah, think about this for just a second.

As we almost constantly discuss, habitats like flooded forests, meadows, vernal pools, igarape, and swollen streams tend to encompass terrestrial habitats, or go through phases where they are terrestrial habitats for a good part of the year.

In these wild habitats, the leaves, branches, soils, and other botanical materials remain in place, or are added to by dynamic, seasonal processes. For the most part, the soil, branches, and a fair amount of the more "durable" seed pods and such remain present during both phases. 

The formerly terrestrial physical environment is now transformed into an earthy, twisted, incredibly rich aquatic habitat, which fishes have evolved over eons to live in and utilize for food, protection, and complex, protected spawning areas. 

All of the botanical material-shrubs, grasses, fallen leaves, branches, seed pods, and such, is suddenly submerged; often, currents re-distribute the leaves and seed pods and branches into little pockets and "stands", affecting the (now underwater) "topography" of the landscape.

Leaves begin to accumulate. Detritus settles.

Soils dissolve their chemical constituents- tannins, and humic acids- into the water, enriching it. Fungi and micororganisms begin to feed on and break down the materials. Biofilms form, crustaceans multiply rapidly.  Fishes are able to find new food sources; new hiding places..new areas to spawn.

Life flourishes.

Similar to what should happen in our aquaria, right?

The longer these materials are present in the ecosystem, the more they are utilized along the food chain by various aquatic life forms.

I have long believed that if you decide to let the botanicals remain in your aquarium to break down and decompose completely, you shouldn't change course by suddenly removing the material all at once...Particularly if you're going to a new version of an existing aquarium.

Why? 

Well, I think my theory is steeped in the mindset that you've created a little ecosystem, and if you start removing a significant source of someone's food (or for that matter, their home!), there is bound to be a net loss of biota...and this could lead to a disruption of the very biological processes that we aim to foster. I think that we should continuously add more materials into the aquarium to replace those which have broken down.

Okay, it's a theory...But I think I might be on to something, maybe? So, like here is my theory in more detail:

Simply look at the botanical-style aquarium (like any aquarium, of course) as a little "microcosm", with processes and life forms dependent upon each other for food, shelter, and other aspects of their existence. And, I really believe that the environment of this type of aquarium, because it relies on botanical materials (leaves, seed pods, etc.), is more significantly influenced by the amount and composition of said material to "operate" successfully over time. As existing material break down, new ones are constantly being added back into the environment. 

Yeah, there is a natural "prototype" for this process.

And, in the aquarium, we can embrace this and replicate it.

This is similar to the Japanese aquascaping practice of "sozo haishoku" espoused by the "Master" of this in aquariums, the late Takashi Amano. This is the processs of removing of as much old substrate material as possible along with the plants it contains in an aquarium, and replacing them with new materials.

It preserves the overall "composition" of the layout, but the "softscape" (botanicals and leaves, in our case) could change dramatically.

As we talked about many times before, removing old materials and replacing them with new stuff does sort of mimic what happens in many streams and rivers on a seasonal basis: Older materials are swept downstream as the watercourses swell, and are replaced by new ones that arrive to replace them.

And of course, in the aquarium, performing a "sozo haishoku"-type replacement of materials can significantly change the aesthetic of the aquascape because the botanicals are replaced with different ones after the previous ones are removed. In Nature, the underwater "topography" is significantly affected by these events, removing old feats and replacing them with new ones.

On the "downside", it can also create significantly different environmental parameters when we do big "change-ups" of materials in a short span of time; the impacts on our fishes may be positive or negative, depending upon the conditions which existed prior to the move. 

Okay, I might just be torturing this simple idea to death- I admit this point that I'm probably not adding much more to the "recipe" here; likely simply being redundant and even a bit vague...However, I think we need to think about how interesting and indeed, transformative this simple practice is.

And yeah, I'll concede that we probably don't have every answer on the processes which govern this stuff.

For example:

The most common question I get when it comes to taking out a fair amount of this material and then "continuing" the tank is, "Will it cycle again?"

And the answer is...Sure, it could.

On the other hand, here is my personal experience:

Remember, I keep a sort of diary of most of my aquarium work. I have for over three decades (gulp...). Just random scanning my "diary", I see that I have executed this practice dozens of times in all types of aquariums, ranging from simple planted aquariums to hardscape-only tanks, to botanical-style, blackwater and brackish aquariums, to reef tanks.

Not once- as in never- have I personally experienced any increase in ammonia and nitrite, indicative of a new "cycle."

Now, this doesn't mean that I guarantee a perfect, "cycle-free" process for you.  I'd be a complete asshole if I asserted that!

On the other hand, by leaving the bulk of the substrate material intact, and continuing to provide "fuel" for the extant biotia by leaving in and adding to the botanicals present in the aquarium, this makes a lot of sense.

I personally think our botanical-style systems, with their diverse and dynamic biology, rebound quickly. Much like the natural systems they purport to represent.

Sure, I have in place a mindset and husbandry practices that assure success with this idea.

Personally, I don't think that botanical-style aquarium are ever "finished." They simply continue to evolve over extended periods of time, just like the wild habitats that we attempt to replicate in our tanks do...

Endless.

Stay engaged. Stay creative. Stay bold. Stay excited...

And Stay Wet.

Scott Fellman

Tannin Aquatics