We talk a lot about starting up and managing botanical-style aquariums. We have had numerous discussions about set up and the accompanying expectations of the early days in the life of the little ecosystems we've created. However, what about the long term..The really long term?
Like, how long can you maintain one of these aquariums?
Do they have an "expiration date? A point when the system no longer "grows" or thrives?
There is a term, sometimes used to describe the state of very old aquariums- "senescence." The definition is: "...the condition or process of deterioration with age." Well, that doesn't sound all that unusual, right? I mean, stuff ages, gets old, stops functioning well, and eventually expires...aquariums are no different, right?
Well, I don't think so.
Sometimes, this deterioration is referred to in the hobby by the charming name of "Old Tank Syndrome"
Now, on the surface, this makes some sense, right? I mean, if your tank has been set up for several years, environmental conditions will change over time. Among the many phenomenon brought up by proponents of this theory is the increase in nitrate levels. People who buy into "OTS" will tell you that nitrate levels will increase over time.
They'll tell you that phosphate, which typically comes into our tanks with food, will accumulate, resulting in excessive, perhaps rampant, algal growths. You know, the kind from which aquarium horror stories are made.
They will tell you that the pH of the aquarium will decline as a result of accumulating nitrate, with hydrogen ions utilizing all available buffers, resulting in a reduction of the pH below 6 (like, IS that a problem?), which supposedly results in the beneficial bacteria ceasing to convert ammonia into nitrite and nitrate and creating a buildup of toxic ammonia...
I mean, it's absolutely possible. We've talked about the potential cessation of the nitrogen cycle as we know it at low pH levels, and about the archaens which take over at these low pH levels. (That's a different "thing", though, and off topic ATM)
Of course, all of the bad things espoused by the OTS theorists can and will happen...If you never do any tank maintenance. If you simply abandon the idea of water exchanges, continue stocking and feeding your aquarium recklessly, and essentially abandon the basic tenants of aquarium husbandry.
The problem with this theory is that it assumes all aquarists are knuckleheads, refusing to perform water exchanges, while merrily going about their business of watching the pretty fishes swim. It seems to forecast some sort of inevitability that this will happen to every tank.
No way. Uh-uh. I call B.S. on this.
As someone who has kept all sorts of tanks (reef tanks, freshwater fish-only tanks, etc.) in operation for many years (my longest was 13 years, and botanical-style tanks going on 5 plus years), I can't buy into this idea. I mean, sure, if you don't set up a system properly in the first place, and then simply become lackadaisical about husbandry, of course your tank can decline.
But, here's the thing: It's not inevitable.
RULE OF THUMB: Do fucking maintenance, feed carefully, and don't overstock. This is not "rocket science!"
Rather than "Old Tank Syndrome"- a name which seems to imply that it's not our fault, and that it's like some unfortunate, random occurrence which befalls the unsuspecting-we should call it LAAP- "Lazy Ass Aquarists' Payback."
'Cause that's what it IS. It's entirely the fault of a lazy-ass aquarist. Preventable and avoidable.
Need more convincing that it's not some random "malady" that can strike any tank? That it's some "universal constant" which commonly occurs in all aquariums?
Think about the wild habitats which we attempt to model our aquariums after. Do these habitats decline over time for no reason? Generally, no. They will respond to environmental changes, like drought, pollution, sedimentation, etc. They will react to these environmental pressures or insults. They will evolve over time.
Now, sure, seasonal desiccation and such result in radical environmental shifts in the the aquatic environment and a definite "expiration date"- but you seldom hear of aquatic habitats declining and disappearing or becoming otherwise uninhabitable to fishes without some significant (often human-imposed) external pressures- like pollution, ash from fires or volcanoes, deliberate diversion or draining of the water source (think "Rio Xingu"), logging operations, climate change, etc.
Of course, our aquariums are closed ecosystems. However, the same natural laws which govern the nitrogen cycle or other aspects of the system's ecology in Nature apply to our aquariums. The big difference is that our tanks are almost completely dependent upon us as aquarists applying techniques which replicate some of the factors and processes which apply in Nature. Stuff like water exchanges, etc.
So if we keep up the nutrient export processes, don't radically overstock our systems, feed appropriately, maintain filters, and observe them over time, there is no reason why we couldn't maintain our aquariums indefinitely.
There is no "expiration date."
And the cool thing about botanical-style aquariums is that part of our very "technique" from day one is to facilitate the growth and reproduction of beneficial microfauna, like bacteria, fungal growths, etc., and to allow decomposition to occur to provide them feeding opportunities.What this does is help create a microbiome of organisms which, as we've said repeatedly, form the basis of the "operating system" of our tanks.
Each one of these life forms supporting, to some extent, those above...including our fishes.
So, yeah- botanical-style aquariums are "built" for the long run. Provided that we do our fair share of the work to support their ecology. Just because we add a lot of botanical material, allow decomposition, and tend to look on the resulting detritus favorably doesn't mean that these are "set-and-forget" systems, any more than it means they're particularly susceptible to all of the problems we discussed previously.
Common sense husbandry and observation are huge components of the botanical-style aquarium "equation."
As part of our regular husbandry routine, we keep the ecosystem "stocked" with fresh botanicals and leaves on a continuous basis, to replenish those which break down via decomposition. This is perfectly analogous to the processes of leaf drop and the influx of allochthonous materials from the surrounding terrestrial habitat which occur constantly in the wild aquatic habitats which we attempt to replicate.
We favor a "biology/ecology first" mindset.
Replenishing the botanical materials provides surface area and food for the numerous small organisms which support our systems. It also provides supplemental food for our fishes, as we've discussed previously. It helps recreate, on a very real level, the "food webs" which support the ecology of all aquatic ecosystems.
And it sets up botanical-style aquariums to be sustainable indefinitely.
Radical moves and "Spring Cleanings" are not only unnecessary, IMHO- they are potentially disruptive and counter-productive. Rather, it's about deliberate moves early on, to facilitate the emergence of this biome, and then steady, regular replenishment of botanical materials to nourish and sustain the ecosystem.
My belief is steeped in the mindset that you've created a little ecosystem, and that, 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.
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 significantly influenced by the amount and composition of said material to "operate" successfully over time.
No expiration date.
Personally, I don't think that botanical-style aquariums are ever "finished", BTW. They simply continue to evolve over extended periods of time, just like the wild habitats that we attempt to replicate in our tanks do.
The continuous change, development, and evolution of aquatic habitats is a fascinating, compelling area to study- and to replicate in our aquaria. I'm convinced more than ever that the secrets that we learn by fostering and accepting Nature's processes and dynamics are the absolute key to everything that we do in the aquarium.
The idea that your aquarium environment simply deteriorates as a result of its very existence is, in my humble opinion, wrong, narrow-minded, and outdated thinking. (Other than that, it's completely correct!😆).
"Old Tank Syndrome" is a crock of shit, IMHO.
Aquariums only have an "expiration date" if we don't take care of them. Period. No more sugar coating this.
If we look at them assume sort of "static diorama" thing, requiring no real care, they definitely have an "expiration date"; a point where they are no longer sustainable. When we consider our aquariums to be tiny, closed ecosystems, subject to the same "rules" which govern the natural environments which we seek to replicate, the parallels are obvious. The possibilities open up. And the potential to unlock new techniques, ideas, and benefits for our fishes is very real and truly exciting!
I'm not entirely certain how this approach to aquariums, and this idea of fostering a microbiome within our tank and caring for it has become a sort of "revolutionary" or "counter-culture" sort of thing in the hobby, as many fellow hobbyists have told me that they feel it is.
Label it what you want, I think that, if we make the effort to understand the function of our tanks as much as we do the appearance, then it all starts making sense. If you look at an aquarium as you would a garden- an organic, living, evolving, growing entity- one which requires a bit of care on our part in order to thrive-then the idea of an "expiration date" or inevitable decline of the system becomes much less logical.
Rather, it's a continuous and indefinite process.
No "end point."
Much like a "road trip", the "destination" becomes less important than the journey. It's about the experiences gleaned along the way. Enjoyment of the developments, the process. In the botanical-style aquarium, it's truly about a dynamic and ever-changing system. Every stage holds fascination.
An aquatic display is not a static entity, and will continue to encompass life, death, and everything in between for as long as it's in existence. There is no expiration date for our aquariums, unless we select one.
Take great comfort in that simple truth.
Stay grateful. Stay enthralled. Stay observant. Stay patient. Stay dedicated...
And Stay Wet.
By now, this whole idea of adding botanical materials to our aquariums for the purpose of helping create the physical, biological, and chemical environment of our aquariums is becoming way more familiar. Yet, no matter how many times you've created a botanical-influenced natural aquarium, the experience seems new and somehow different.
Expectations are funny things, aren't they?
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!
And yeah, it can even be seen as a bit of a spiritual journey, too- leading to some form of enlightenment and education about Nature, from a totally unique perspective.
The energy and creativity that you bring with you on the journey tends to become amplified during the experience. As you work with botanicals in your aquariums, your mind takes you to different places; new ideas for how your aquarium's microcosm can evolve start flooding your mind. Every tank- like every hobbyist- is different- and different inspirations arise. 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 as a community have learned along the way during our experiences working with botanicals in our aquariums.
Our aquariums evolve, as do the materials within them. We've discussed this concept many times, but it's one that we keep coming back to.
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, or if material gets caught up in filter inlets, etc. However, "operational concerns" aside, and if you've made that "mental shift" and can tolerate the stuff decomposing, 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.
Sometimes, the fishes will use botanical materials for a spawning site.
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 perhaps a slight 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, if you're using activated carbon or other chemical filter media, 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 botanicals are natural materials, there is no "recipe'; no formula with a 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 tinted water, 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. It's something that you either love or simply hate...everyone who ventures into this method of aquarium keeping needs to make their own determination of wether or not they like 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- the function AND the aesthetic-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.
This is the perfect analog to the concept of "allochthonous input" which occurs in wild aquatic habitats- materials from outside the aquatic environment- such as the surrounding forest- entering and influencing the aquatic environment.
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!
Go into this with the expectation that you might get to experience an entirely different way of looking at aquariums- and the natural environments we try to replicate- and you'll never be disappointed.
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.
We so often discuss natural processes and features in our aquarium work.
There are a lot of interesting pieces of information that we can interpret from Nature when planning, creating, and operating our aquariums. The idea of replicating natural processes and occurrences in the confines of our aquariums, by simply setting up the conditions necessary for them to occur is fundamental to our botanical-oriented approach.
It goes without saying that there are implications for both the biology and chemistry of the aquatic habitats when leaves and other botanical materials enter them. Many of these are things that we as hobbyists observe every day in our aquariums!
Well, let's talk about our old friend and sometimes nemesis, biofilm.
A lab study I came upon found out that, when leaves are saturated in water, biofilm is at its peak when other nutrients (i.e.; nitrate, phosphate, etc.) tested at their lowest limits. Hmm...This is interesting to me, because it seems that, in our botanical-style aquariums, biofilms tend to occur early on, when one would assume that these compounds are at their highest concentrations, right? And biofilms are essentially the byproduct of bacterial colonization, meaning that there must be a lot of "food" for the bacteria at some point if there is a lot of biofilm, right?
Does this imply that the biofilms arrive on the scene and peak out really quickly; an indication that there is actually less nutrient in the water? Is the nutrient bound up in the biofilms? And when our fishes and other animals consume them, does this provide a significant source of sustenance for them? Can you have water with exceedingly low nutrient levels, while still having an abundant growth of biofilms?
Oh, and here is another interesting observation:
When leaves fall into streams, field studies have shown that their nitrogen content typically will increase. Why is this important? Scientists see this as evidence of microbial colonization, which is correlated by a measured increase in oxygen consumption. This is interesting to me, because the rare "disasters" that we see in our tanks (when we do see them, of course, which fortunately isn't very often at all)- are usually caused by the hobbyist adding a really large quantity of leaves at once, resulting in the fishes gasping at the surface- a sign of...oxygen depletion?
Makes sense, right?
These are interesting clues about the process of decomposition of leaves when they enter into our aquatic ecosystems. They have implications for our use of botanicals and the way we manage our aquariums. I think that the simple fact that pH and oxygen tend to go down quickly when leaves are initially submerged in pure water during lab tests gives us an idea as to what to expect.
A lot of the initial environmental changes will happen rather rapidly, and then stabilize over time. Which of course, leads me to conclude that the development of sufficient populations of organisms to process the incoming botanical load is a critical part of the establishment of our botanical-style aquariums.
Fungal populations are equally important in the process of breaking down leaves and botanical materials in water as are higher organisms, like insects and crustaceans, which function as "shredders." So the “shredders” – the animals which feed upon the materials that fall into the streams, process this stuff into what scientists call “fine particulate organic matter.”
And that's where fungi and other microorganisms make use of the leaves and materials, processing them into fine sediments. Allochthonous material can also include dissolved organic matter (DOM) carried into streams and re-distributed by water movement.
And the process happens surprisingly quickly, too.
In experiments carried out in tropical rainforests in Venezuela, decomposition rates were really fast, with 50% of leaf mass lost in less than 10 days! Interesting, but is it tremendously surprising to us as botanical-style aquarium enthusiasts? I mean, we see leaves begin to soften and break down in a matter of a couple of weeks- with complete breakdown happening typically in a month or so for many leaves. And biofilms, fungi, and algae are still found in our aquariums in significant quantities throughout the process.
So, what's this all mean? What are the implications for aquariums?
I think it means that we need to continue to foster the biological diversity of animals in our aquariums- embracing life at all levels- from bacteria to fungi to crustaceans to worms, and ultimately, our fishes...All of which form the basis of a closed ecosystem, and perhaps a "food web" of sorts for our little aquatic microcosms.
It's a very interesting concept- a fascinating field for research for aquarists, and we all have the opportunity to participate in this on a most intimate level by simply observing what's happening in our aquariums every day!
And facilitating this process is remarkably easy:
*Approach building an aquarium as if you are creating a biome.
*Foster the growth and development of a community of organisms at all levels.
*Allow these organisms to grow and multiply.
*Don't "edit" the growth of biofilms, fungal growths, and detritus.
By accepting and embracing these changes and little "evolutions", we're helping to create really great functional representations of the compelling wild systems we love so much!
Leaf litter beds, in particular, tend to evolve the most, as leaves are among the most "ephemeral" or transient of botanical materials we use in our aquariums. This is true in Nature, as well, as materials break down or are moved by currents, the structural dynamics of the features change.
We have to adapt a new mindset when aquascaping with leaves- that being, the 'scape will "evolve" on its own and change constantly...Other than our most basic hardscape aspects- rocks and driftwood- the leaves and such will not remain exactly where we place them.
To the "artistic perfectionist"-type of aquarist, this will be maddening.
To the aquarist who makes the mental shift and accepts this "wabi-sabi" idea (yeah, I'm sort of channeling Amano here...) the experience will be fascinating and enjoyable, with an ever-changing aquascape that will be far, far more "natural" than anything we could ever hope to conceive completely by ourselves.
It's not something to freak out about.
Rather, it's something to celebrate! Life, in all of it's diversity and beauty, still needs a stage upon which to perform...and you're helping provide it, even with this "remodeling" of your aquascape taking place daily. Stuff gets moved. Stuff gets covered in biofilm.
Stuff breaks down. In our aquairums, and in Nature.
Some people cannot fully grasp that.
Recently, I had a rather one-sided "discussion" (actually, it was mostly him attacking) with a "fanboy" of a certain style of aquarium keeping, who seemed to take a tremendous amount of pleasure in telling me that "our interpretation of Nature" and our embrace of decomposing leaves, biofilms, detritus, and such is a (and I quote) "...setback for the hobby of aquascaping..." (which, those of you who know me and my desire to provoke reactions, understand that I absolutely loved hearing!) and that "it's not possible to capture Nature" with our approach... (an ignorant, almost beyond stupid POV. I mean, WTF does "capture Nature" mean? Word salad.)
I was like, "C'mon, dude. Really? This is NOT a style of aquascaping!"
We repeat this theme a million times a year here: Nature is really not always clean and tidy. In fact- most of the time, it isn't. And if you buy into the head-scratching hobby narrative that every pristine "high-concept" contest aquarium is somehow what Nature "looks like", you're simply fooling yourself.
Sure, there are some really clear, sparkling habitats out there in the world, but they represent the exception, really.
Additionally, I'll go out on a limb and suggest that none of them have tidy rows of symmetrically trimmed, color- balanced plants, or neatly arranged rocks of related size and proportion. 😆
This is directed at a small, but vocal, and apparently misinformed crowd, but I can't stress this enough:
If you really want to understand the natural aquatic habitats of our fishes, some of you have to get out of the idealized aquascaping mindset for a bit and stop dissing everything that doesn't fit your idea of the way the world should be, and just accept the realities which Nature presents...
I am actually surprised we still get the occasional DM like this.
So I occasionally push back a bit.
Okay, I'm not bragging that our avant-garde love of dirty, often chaotic-looking aquariums makes us cooler than the "sterile glass pipe-loving aquascaping crowd. It's not really even a comparison, but its typically that crowd which hurls the insults at our approach, so...😆
However, I do want everyone to understand the degree to which we love the concept of Nature in it's most compelling form, and how strongly we feel that we, as a global community of hobbyists need to look beyond what's regularly presented to us as a "natural aquarium" and really give this stuff some thought. We CAN and SHOULD interpret natural aquatic features more literally in our aquairums.
Now, not all of Nature requires us to make extreme aesthetic preference shifts in order to love it.
Well, maybe not all. A lot of it, though.
It's a very different type of "aesthetic beauty" than we are used to. It's an elegant, remarkably complex microhabitat which is host to an enormous variety of life forms. And it's a radical departure from our normal interpretation of how a tank should look. It challenges us, not only aesthetically- it challenges us to appreciate the function it can provide if we let it.
"Functional aesthetics." Again.
Our "movement" believes in representing Nature as it exists in both form and function, without "editing" the very attributes of randomness and resulting function that make it so amazing.
And it all starts with understanding and facilitating natural processes without "editing" them to meet some ingrained aesthetic preferences.
Can you do that? Can you make that mental shift?
I hope so. We'd love to have you here!
Stay bold. Stay curious. Stay patient. Stay observant. Stay creative. Stay enthralled...
And Stay Wet.
Of all of the topics we cover here in "The Tint", the one we discuss the least (rather shockingly, I might add) is the fishes that we keep in our tanks! Yeahs, I talk more about fungi, sediments, decomposition, and leaf litter than I do about fishes...
And of course, when someone hit me up the other day and asked, "Scott, what are your favorite fishes for botanical-style aquariums?" I was like, "Well, shit- I never even covered that!" I mean, we should have covered that before. It's a cool topic. I'm kind of unsure why, actually.
Probably because most of the articles on this topic are kind of...oh, crap, I'll say it- just boring. Ever read one of those "Top 10" listicle thingys about fishes? They usually-well, suck. Harsh, but they're kind of boring, IMHO. I mean, they talk about the size of the fish, what it eats, and what size tank you can keep it in. I mean, helpful, but..I dunno. Boring. Stuff you can pretty much find in any aquarium-related reference. You don't come here for that, I hope... So, we'll try to cover these fishes from "a slightly different perspective", as I like to say.
So, let's hit that topic today! Okay, let's hit some of it today...my list is longer than my patience to discuss them all in one piece! And I'll try my best not to do it the boring way...
Oh, damn, I might have a bunch of fishes...but I don't think I'm gonna cover all of them today...
Give me a break- it's a start, right?
Now, here's the thing- you'll find that my fish choices are as much based upon the habitats that they come from as they are about the fishes themselves..
Okay, so let's get this party started...
In no particular order ( well, maybe in a sort of order..):
Sailfin Characin (Crenuchus spilurus)
We've all had that ONE fish which just sort of occupies a place in our hearts and minds- a fish that-for whatever reason- bites you and never lets go, right? I think that every serious aquarist has at least one such a fish..
Of course, it's also about the habitat which this fish lives in that's kept me under its spell for so long...
As a lover of leaf-litter in our natural, botanical-style aquariums, I am fascinated not only by this unique ecological niche, but by the organisms which inhabit it. I've went on and on and spoken at length about many of the microorganisms, fungi, insects, and crustaceans which add to the diversity of this environment. And of course, we've looked at some of the fishes which live there, too! Perhaps not enough, actually...
One of my all-time favorite fishes- and my absolute favorite characin is none other than the amazing "Sailfin Tetra", Crenuchus spilurus! This is a truly awesome fish- not only is it attractive and morphologically cool-looking, it has a great demeanor and behaviors which separate it from almost every other characin out there!
I first fell for this fish as a kid, when I saw a cool pic of it in my dad's well-worn copy of William T. Innes' classic book, Exotic Aquarium Fishes. The book that pretty much assured me from toddler days that I'd be a fish geek. I obsessed over the book before I could even read...
I was hooked from the start with Crenuchus, especially when reading about the romantic etymology of the name! And it just seemed so "mysterious" and unattainable, even in the 1930's...well, especially back in the 1930's, but it seemed downright exotic! To this day, it's one you just don't see too much of in the hobby. And then, tying it together with my love of those leaf-litter-strewn habitats, it was a combo which I couldn't resist!
I never got this fish out of my system, and it took me like 30-plus years of being a fish geek to find this fish in real life. And, you know that I jumped at the chance..It was so worth the wait!
It's almost "cichlid-like" in behavior: Intelligent, interactive, and endearing. It has social behaviors which will entertain and fascinate those who are fortunate enough to keep it.
Now, I admit, it's definitely NOT the most colorful characin on the planet. But there is more than this fish than meets the eye.
It all starts with its most intriguing name...
The Latin root of the genus Crenuchus means "Guardian of The Spring"- a really cool, even romantic-sounding name which evokes imagery-and questions! Does it mean the "protector" of a body of water, or some honorary homage to everyone's favorite season? Not sure, but you must agree that the name is pretty cool! In greek, it's krenoychos -"The God of running waters."
Yeah. That's the shit. I mean, do Latin names get any cooler than that?
The Crenuchidae (South American Darters) is a really interesting family of fishes, and includes 93 species in 12 genera throughout the Amazon region. Most crenuchids are- well, how do we put it delicately- "chromatically challenged" ( ie; grey-black-brown) fishes, which tend to lie in wait near the substrate (typically leaf litter or aggregations of branches), feeding on insects and micro invertebrates. And the genus Crenuchus consists of just one species, our pal Crenuchus spilurus, a fish which shares habits and a body shape that are more commonly associated with Cyprinids and...cichlids!
That's just weird.
Now, the relatively subdued coloration serves a purpose, of course. These fishes live among leaf litter, root tangles, and botanical debris..in tinted water...which demand (if you don't want to be food for bigger fishes and birds) some ability to camouflage yourself effectively.
The Sailfin is an exception to the "drab" thing, and it's remarkably attractive for a very "simple" benthic-living fish. Sure, on the surface, it's not the most exciting fish out there, especially when it's a juvenile...but it's a fish that you need to be patient with; a fish to search for, collect, hold onto, and enjoy as it matures and grows. As the fish matures, in true "ugly duckling"🐥 style, it literally "blossoms" into a far more attractive fish.
The males have an extended dorsal and anal fin, and are larger and more colorful than females. Yes, colorful is relative here, but when you see a group- you'll notice the sexual dimorphism right away, even among juveniles.
Individuals spend a lot of their time sheltered under dead leaves, branches, roots, and aquatic plants. They tend to "hover", and don't dart about like your typical Tetra would. In fact, their behavior reminds me of the Dartfishes of the marine aquarium world...They sort of sit and flick their fins, often moving in slow, deliberate motions. Communication? Perhaps.
The Sailfin feeds during the daylight hours, and spends much of its day sheltering under branches, leaves, and root tangles, and is a mid-water feeder, consuming particulate organic matter, such as aquatic invertebrates, insects, bits of flowers, and fruits- the cool food items from outside of the aquatic environment that form what ecologists call allochthonous input-materials from outside of the aquatic habitat, which are abundant in the terrestrial habitats surrounding the aquatic ones which we love to model our aquariums after.
Tucano Tetra (Tucanoichthys tucano)
You all know by now that my philosophy is to study and understand the environments from which our fishes come, and to replicate them in function and form as best as possible. It doesn't always mean exactly- but it's definitely NOT forcing them to adapt to our "local tap water "conditions without any attempt to modify them.
I have a very current "case study" of my own that sort of reflects the execution of my philosophy.
As many of you know, I've had a long obsession with the idea of root tangles and submerged accumulations of leaves, branches, and seed pods. I love the silty, sedimented substrates and the intricate interplay of terrestrial plant roots with the aquatic environment.
I was doing a geeky "deep dive" into this type of habitat in Amazonia one evening, and stumbled upon this gem from a scientific paper by J. Gery and U. Romer in 1997:
"The brook, 80-200cm wide, 50-100 cm deep near the end of the dry season (the level was still dropping at the rate of 20cm a day), runs rather swiftly in a dense forest, with Ficus trees and Leopoldina palms...in the water as dominant plants. Dead wood. mostly prickly trunks of palms, are lying in the water, usually covered with Ficus leaves, which also cover the bottom with a layer 50-100cm thick. No submerse plants. Only the branches and roots of emerge plants provide shelter for aquatic organisms.
The following data were gathered by the Junior author Feb 21, 1994 at 11:00AM: Clear with blackwater influence, extremely acid. Current 0.5-1 mv/sec. Temp.: Air 29C, water 24C at more than 50cm depth... The fish fauna seems quite poor in species. Only 6 species were collected I the brook, including Tucanoichthys tucano: Two cichlids, Nannacara adoketa, and Crenicichla sp., one catfish, a doradid Amblydoras sp.; and an as yet unidentified Rivulus, abundant; the only other characoid, probably syncopic, was Poecilocharax weitzmani."
Yeah, it turned out to be the ichthyological description of the little "Tucano Tetra", Tucanoichthys tucano, and was a treasure trove of data on both the fish and its habitat. I was taken by the decidedly "aquarium reproducible" characteristics of the habitat, both in terms of its physical size and its structure.
Boom! I was hooked.
I needed to replicate this habitat! And how could I not love this little fish? I even had a little aquarium that I had been dying to work with for a while.
It must have been "ordained" by the universe, right?
Now, I admit, I wasn't interested in, or able to safely lower the pH down to 4.3 ( which was one of the readings taken at the locale), and hold it there, but I could get the "low sixes" nailed easily! Sure, one could logically call me a sort of hypocrite, because I'm immediately conceding that I won't do 4.3, and I suppose that could be warranted...
However, there is a far cry between creating 6.2pH for my tank, which is easy to obtain and maintain for me, and "force-fitting" fishes to adapt to our 8.4pH Los Angeles tap water!
And of course, with me essentially trashing the idea of executing a hardcore 100% replication of such a specific locale, the idea was essentially to mimic the appearance and function of such an igarape habitat, replete with lots of roots and leaf litter.
And the idea of executing it in a nano-sized aquarium made the entire project more immediately attainable and a bit less daunting. I wanted to see if I could pull off a compelling biotope-inspired aquairum on a small scale.
That's where my real interest was.
So, even the "create the proper conditions for the fish instead of forcing them to adapt to what's easiest for us" philosophy can be nuanced! And it should! I don't want to mess with strong acids at this time. It's doable...a number of hobbyists have successfully. However, for the purposes of my experiment, I decided to happily abstain for now, lol.
And without flogging a dead horse, as the horrible expression goes, I think I nailed many of the physical attributes of the habitat of this fish. By utilizing natural materials, such as roots, which are representative of those found in the fish's habitat, as well as the use of Ficus and other small leaves as the "litter" in the tank, I think we created a cool biotope-inspired display for these little guys!
And man, I love this tank!
Being able to pull off many aspects of the look, feel and function of the natural habitat of the fish was a really rewarding experience. A real "case study" for my philosophy of fish selection and stocking.
Green Neon Tetra (Paracheirodon simulans)
Everyone knows the Neon Tetra, Paracheirodon inessi. It's a strong candidate for the title of "Official fish of the Aquarium Hobby!" 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 (less romantically 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 present all or part of the time.
(Image by G. Durigan)
So, if you really want to get hardcore about 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 and fallen palm fronds...This is right up our alley, right?
Of course, if you really want to be a full-on "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.
The 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? Shallow! I mean, we can utilize all sorts of aquariums and accurately recreate the depth of the habitats which P. simulans comes from!
We often read in aquarium literature 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).
So, maybe you've noticed a pattern to my love of certain fishes...so much is based upon the habitats that they come from. My love for the fishes was amplified when I studied and learned more about the unique habitats from which each of these fishes come. The idea of recreating various aspects of the habitat as the basis for working with these fishes is irresistible to me!
Diptail or Brown Pencilfish (Nanostomus eques)
This one really should have been the top choice if I were doing it in order. I LOVE everything about this fish. Well, almost everything.
Honestly, if a fish could earn the moniker "cool", this little guy would be it. It's absolutely not an overstatement to declare that these Pencilfishes have distinct personalities! They're not "mindless-drone, stupid schooling fishes", like some of the Tetras. (Sorry, my homies...Love ya' lots, but alas- you have no individual personalities...😂)
They are proud members of the family family Lebiasinidae. It was first described in 1876 by the legendary ichthyologist, Franz Steindachner. In fact, it was one of the first members of the genus Nanostomus to be discovered and described by science.
Cool, but that's not my main reason for loving this fish. There's a bunch of unique aspects to this fish's behavior which I find enormously compelling.
The Latin name of the species, eques, means "knight", "horseman", or "rider", in reference to this species’ unique oblique swimming angle.
Ah, that "oblique swimming angle" thing. Yeah, they swim at an angle of about 45 degrees facing upwards. This angle is thought to give them an advantage in feeding. They see insects and such that fall from overhanging vegetation better than their horizontally-oriented buddies do. They get more food that way. Simple.
(Image by Fajoe, used under CC BY-SA 3.0)
What I really love about these fish is that they are incredibly curious and obviously intelligent, checking out just about anything which goes on in their aquarium. You get the feeling when observing them that they are acutely aware of their surroundings, and once acclimated, are pretty much fearless. A fellow hobbyist once told me she thinks they're the freshwater equivalent of Pipefish...and that sounds about right..I agree with that 100%!
They're sociable, incredibly "chill" fish. Now, the thing about their ability to adeptly feed on allochthonous input into the aquatic environment makes them easy to feed. And it also gives you some clues as to the habitats they come from. Places where the food comes from the surrounding terrestrial environment.
Foods from the surrounding environment, such as flowers, fruits, terrestrial insects, etc. These are extremely important foods for many fish species that live in these habitats. We mimic this process when we feed our fishes prepared foods, as stuff literally "rains from the sky!" Now, I think that what we feed to our fishes directly in this fashion is equally as important as how it's fed.
The environments which provide this food abundance also provide lots of opportunities to replicate in our aquariums. I love that about this fish. They come from really cool, really inspiring habitats.
They are also really adept at picking on epiphytic materials in their botanical-style aquariums. It's an observation I've made many times with these fish.
Yeah, they seem to spend a large amount of time picking at biofilm and other material adhering to botanicals, and specifically, wood. They engage in this activity almost constantly throughout the day (between feedings, of course!). I am convinced that they are likely not specifically targeting the biofilm directly; rather, I think that they're looking for tiny crustaceans and other life forms that live in the matrix.
Nonetheless, their picking distrubs the films and puts it into suspension, where it can more easily be removed by filtration. This was an unexpected "plus" of this most beloved group of fishes. Now, I must warn you, biofilm haters- you shouldn't even consider Pencilfishes as a biofilm "control mechanism", but I suppose that to you heathens, the "collateral benefit" is nice.
They are very aware, very adept feeders...Always ready to pounce.
What's the thing I don't like about these fish?
Oh, they can be a bit skittish. Like, chill as they are, "stuff" just freaks them out.
They will, for seemingly no reason, launch themselves out of your open-top aquarium (well, those are the only types I keep...) with tremendous agility-sometimes landing a few inches away in the tank...Other times, completely leaving the tank, and well- usually this results in a very dried-out Pencilfish!
I guess the oblique swimming angle facilitates them reaching "escape velocity" rapidly. You get the feeling that they're always in "standby for launch!" mode. Like, full-on "defcon-5" mode.
Maybe, because they're always looking UP- the slightest disturbance from BELOW triggers a launch. I don't know, but it's as good a theory as any. And a 3-inch launch gets you away from a potential predator. A 6-inch launch lands you on the floor... Damn, a good adaptation for protection, this "launching" thing. But, like, who really wants to eat a Pencilfish, right? I guess the Pencilfish don't know that...They just jump. Millenia of genetic programming can't be overcome easily!
It sucks, but it's the downside to keeping them in open-top tanks. Lots of twisted branches and even floating plants DO help limit some of this "carpet surfing" behavior, but it's not a 100% perfect solution. I admit, These guys have, in the past played a central role in some of those "And then there were none" disappearing fish sagas that I've experienced over the years.
So, if you can keep them in a low- traffic area, employ lots of branches, and maybe some floating plants...maybe you'll avoid this.
I mean, these methods also occasionally work with Hatchetfishes...another fave of mine, but almost too suicidal, even for me. And that's why they are not in my top 10 list, if you're wondering..
Okay, I could probably do a top 10, or even a dozen- fave fishes, but I'd be writing all day on this topic. Honorable mention- The Checkerboard Cichlid (Dicrossus filamentosus)... My "go-to" cichlid for botanical-style tanks...I love them- even over Apistos...And, as one of my friends told me, "Of course you do Scott- they're fucking brown!"
Damn, my friends really know me well, huh?
Just try them in your next botanical-style aquarium. You won't regret it. Maybe we'll deep dive in the "Fellman style" on these guys next time...
Okay that's a start... I think I can safely employ the great line used by one of the aquarium hobby's great saltwater fish experts, Scott Michael, who, upon discussing such-and-such a fish would simply declare in a deadpan manner, "If you don't keep these fish, you're stupid.."
How can you argue with THAT kind of assertion? I totally relate to that. Well, shit- you asked me what my faves are...you knew I'd have some strong feelings about them, huh? 😆
Anyhow, I hope this little start gives you a look into the unorthodox way I think about the fish I select for my aquariums: So much of it is about studying a habitat I love, and then researching what fishes are found in it- and why. Then, creating the habitat for them. Like, "habitat-first." Totally works for me.
I hope it works for you too!
Until Next time...
Stay thoughtful. Stay curious. Stay bold. Stay diligent...
And Stay Wet.
One of the best things about not having a lot of tanks in operation at the moment (Wait, let's correct that...the ONLY good thing about not having a lot of tanks in operation at the moment...😆) is that it gives you the opportunity to plan, review, and plot your next moves.
I'm in such a phase at home, with my house undergoing a substantial remodel and all of my "full-size" tanks in storage for a couple more months. As I've told you previously, it's given me the opportunity to play with a lot of ideas quickly in "nano-sized" aquariums.
And of course, I've thought s lot about how I'm going to start up my next botanical-style tanks.
Here's an approach I'm trying on one of them. I call it the "transitional" approach.
Okay, we've tackled our "Urban Igapo" idea a bunch of times here, with the technique being described and studied quite a bit. Now, the repetition of wet and dry "seasonal cycles" in the aquarium, although fascinating and the most novel takeaway from this approach, is but one way to apply the idea of evolving a "dry forest floor" into an aquatic habitat.
This is one of the most incredible and fascinating ecological dynamics in Nature, and it's something that we as a hobby have not attempted to model to any extent, until we started messing around with the idea of replicating it around 2017. Again, we're not talking about replicating the 'look" of a flooded forest after it's been flooded...That has been done for years by hobbyists, particularly in biotope design contests. An "aquascaping" thing.
This is a bit different.
We're talking about actually replicating and flooding the damn forest floor! Replicating the cycle of inundation. It's a functional approach, requiring understanding, research, and patience to execute. And the aesthetics...They will follow, resembling what you see in Nature. But the primary reason is NOT for aesthetics...
So, the way this would work is to simply set up the tank like our "standard" approach to creating an "Urban Igapo"- utilizing a sedimented substrate (um, yeah, we make one....) to create a "forest floor." And then, you add leaves, botanicals, and perhaps, some terrestrial grass seeds, and even riparian plants.
You'd set whatever "hardscape" you want- driftwood, etc. in place. Of course, you'd have to water your little forest floor for some period of time, allowing the vegetation to sprout and grow. Based on the many times of played with the "Igapo" idea, this process typically takes around 2-3 months to establish the growth well.
And then what? Well, you'd flood it!
You could do this all at one time, or over the course of several days, depending upon your preference. I mean, you've waited a couple of months to add water to your tank...what's another few days? 😆 Now, sure, there's a difference between a 5-gallon tank and a 50- gallon tank, and it takes a lot longer to fill, so it's up to you how you want to approach this!
And what you'd initially end up with is a murky, tinted environment, with little bits of leaves, botanicals, and soil floating about. Sounds like a blast, huh? And when you think about it, this is not all that different, at least procedurally, from the "dry start" approach to a planted tank...except we're not talking about a planted tsmnk here.. I mean, you could do aquatic plants...but it's more of a "wholistic biome" approach...
The interesting thing about this approach is that you will see a tank which "cycles" extremely quickly, in my experience. In fact, Iv'e done many iterations of "Urban Igapo" tanks where there was no detectible "cycle" in the traditional sense. I don't have an explanation for this, except to postulate that the abundance of bacterial and microorganism growth, and other life forms, like fungal growths, etc., powered by the nutrients available to them in the established terrestrial substrate expedites this process dramatically.
That's my theory, of course, and I could be way, way off base, but it is based on my experience and that of others in our community over the past several years. I mean, there is a nitrogen cycle occurring in the dry substrate, so when it's inundated, do the bacteria make the transition, or do they perish, followed by the very rapid colonization by other species, or..?
An underwater biome is created immediately with this approach. Doing this type of "transition" is going to not only create a different sort of underwater biodiversity, it will have the "collateral benefit" of creating a very different aesthetic as well. And yeah, it's an aesthetic that will be dictated by Nature, and will encompass all of those things that we know and love- biofilms, fungal growth, decomposition, etc.
I've done this in aquariums up to 10 gallons so far, with great success, so I'm completely convinced that this process can be "scaled up" easily. The technique is the same.
Now, one fundamental difference between this approach and the more "traditional" "Urban Igapo" approach is that it's a "one way trip"- start our dry and take it to "wet", without going through repetitive dry cycles. The interesting thing to me about this approach is that you're going to have a very nutrient-rich aquarium habitat, with a big diversity of life from the start.
It's still early days.
There is so much to learn and experiment with. Every single one of us, when we embark on a botanical-style aquarium adventure- is playing a key role in contributing to the "state of the art" of the aquarium hobby! Everycontribution is important...
Enjoy the process!
Stay curious. Stay observant. Stay experimental. Stay bold...
And Stay Wet.