The elegance of simplicity.

I've been hanging out with, talking to, and absorbing a lot of ideas from my friends in the reef community lately, as I've shared with you. It's gotten me to think through a lot of the approaches and ideas which I've had in my head about aquarium management over the years.

There's this thing about "simplicity" and its role in creating and managing successful aquariums over the long term.

One of the interesting things that we see discussed a lot in in the aquarium hobby is the idea of a "balanced aquarium." 

This is hardly a new concept, but it is interesting to think about in the context of simplicity, and modern approaches to aquarium keeping.

The "balanced aquarium" idea was really the first sort of application of the "aquarium as a microcosm" concept. Back in the Victorian era, the balanced aquaria was viewed as a system in which plants and fish could live for years in the same water as long as the ratio of plants and fish were “balanced.”


No water exchanges?

I know, hobbyists have taken this "approach" in all types of tanks for decades with shockingly successful outcomes, but it never sat well with me. I just fail to see what the point is, besides our human interest over all else. And it seems as though it's always discussed in the same breath as the "balanced aquarium..."


IMHO the whole idea of "no water exchanges" is an absurd exercise in laziness. Like, why? Other than not having to spend time on doing water exchanges (IMHO, the easiest part of aquarium maintenance), what's the point? If it's to stick a bg middle finger to the hobby "establishment", there are better ways, trust me.

"No water exchanges."  Eventually, I feel that such a laissez-faire approach will come back to bite you on the ass.

So, that part of the "equation" is a big NO. And aquarists love to couch this in the veil of how it embraces "simplicity" and some sort of "natural approach to the balanced aquarium."

I call bullshit.

It's "simplicity", sure...But let's call it what it really is: It's an abandonment of our responsibilities as aquarists, IMHO. Yeah, simplicity and laziness can be- SHOULD BE- mutually exclusive. It requires more context within the framework of a "balanced aquarium."

And why do we dislike water exchange so much?

Is it the perceived sheer "drudgery" of water exchanges? The manual labor? The potential for spills? Some sort of desire to just focus on other, more interesting aspects of aquarium care and husbandry?

Over the years, in both my writings and practices, I've thought of ways how to represent water exchanges as one of the joys of aquarium keeping- You know, stuff like, "You're diluting some excess dissolved organics in your tank when you do a water exchange!" or, "Water exchanges simulate natural rain and influx/outflow of water in wild habitats!" Or even, "Water exchanges allow you to regularly interact on an intimate basis with your aquarium!"

Like, I can put a positive spin on this- but the bottom line is that aquarists almost universally seem to hate them and accept them as a "necessary evil"...and spend lots of time, money, and effort on ways to make them easier or eliminate them altogether...

Now, this is rather curious: Hobbyists who play in speciality fields- like Discus breeding, so-called "high tech planted tanks", most reefers, and our botanical-style aquarium crowd- seem to embrace water exchanges as just part of the game. Like, you will typically not see tremendous efforts to circumvent them being made- at least not publicly! 

We probably have reconciled- particularly as botanical-style aquarium enthusiasts, that water exchanges have huge value to what we do...and they are simply part of the game. 

Further, I can't help but think that the idea of water exchanges can simply be viewed with a different mind set. Really looking to Nature and attempting to view them as more-or-less a simulation of how natural systems work.

I think it's really that simple! 

And this is really the only "intervention" that we typically ask you to make in our relatively "simple" approach...Just exchanging some water regularly.

If you embrace the botanical-style aquarium idea and like it for the "simulation of Nature" part, then it goes without saying that the water exchanges we execute further represent this, and it becomes a lot easier to stomach the idea of siphon hoses, lugging around buckets of water, and the occasional (?) spill?

That should be part of this whole "balanced aquarium" idea... Or, maybe we should just toss the whole term from our hobby lexicon altogether?

Actually, the point of this piece is not to re-hash this well-trodden idea. It's to discuss the idea of running a botanical-style aquarium in a more simple manner.

But, one more thing...

Now, there is another part of the "balanced aquarium" idea that I can get on board with:

It's the idea that the aquarium should provide a significant amount of surface area. In a perfect world, the width of the aquarium should be equal to, and the length double at least of the depth to provide a surface area adequate for gas exchange to take place in an efficient manner.

Gas exchange.

I think that is applicable to almost any type of aquarium, really.

Okay, let me just cut to the chase...The whole idea behind this piece today:

I think that the botanical-style aquarium can be run with a minimal amount of technical gear, intervention, and with simple maintenance procedures.

I think you need the aforementioned gas exchange, facilitated by an aquarium with sufficient surface area. That's a given.

You'd probably want some water movement, and maybe just a bit of surface agitation. I think you could facilitate this water movement and surface agitation with a little surface skimmer, like the ones made by Eheim, Ultum Nature Systems, and Azoo, just to name a few. These are super-cool little devices, as they help remove the surface film caused by an organic-protein layer, facilitating gas exchange. As a plus, the return form these skimmers provide a little bit of water movement.

I'm currently running an ADA 60F (24"x12"x7"/ 60x30x18cm) aquarium, which is about 8.6 U.S. gallons in capacity, solely with one of these devices. It works great!! My previous iteration, the (now famous, to readers of this blog) "leaf litter only" Paracheirodon simulans tank, ran for well over a year like this with tremendous success.

Short of not having any device at all, this is likely as simple as I'd run a botanical-style aquarium. Maybe an auto top-off, but nothing else. 


In a botanical-style aquarium run in this manner, you do have some challenges, of course. You need to stock carefully, being sure not to over-stock your system with fishes- or botanicals- at least, not at once, and not while up and running. We've already talked about the perils of going too fast, too soon. Going slowly and patiently is a long-known key to success with botanical-style aquariums.

Now, nothing is perfect.

And "simplicity of operation" is not the metaphor for "ignorance and abandonment of husbandry."

Nothing we can tell you here is an absolute guarantee of perfect results...You're dealing with natural materials, live animals, and tons of variables; the results you'll see are governed by natural processes that we can only impact to a certain extent by applying logic and common sense. 

One of the most obvious applications of common sense is the way we add botanical materials to our tanks.

And when it comes time to adding your botanicals to your aquarium, the second "tier" of this process is to add them to your aquarium slowly. Like, don't add everything all at once, particularly to an established, stable aquarium. Think of botanicals as "bioload", which requires your bacterial/fungal/microcrustacean population to handle them.

Bacteria, in particular, are your first line of defense.

If you add a large quantity of any organic materials to an established system, you will simply overwhelm the existing beneficial bacterial population in the aquarium, which will likely result in a massive increase in ammonia, nitrite, and organic pollutants. At the very least, it will leave oxygen levels depleted, and fishes gasping at the surface as the bacteria population struggles to catch up to the large influx of materials.

This is not some sort of esoteric concept, right? We know this. OR we should know this, from other aquarium work.

I mean, we don't add 25 3-inch fishes at once to an established, stable 10-gallon aquarium and not expect some sort of negative consequence, right? So why would adding bunch of leaves, botanicals, wood, or other materials containing organics be any different?

It wouldn't.

Common sense is your friend.

And then there's that whole idea of the botanicals themselves functioning as the "filter" of the system, specifically in botanical or leaf litter beds.

I've had some conversations with more science-minded botanical aquarists who postulate about the possibilities of fostering some form of denitrification in (deeper) botanical beds, and it is interesting! One of the questions that seems to come up a lot in this context is the extent to which hydrogen sulfide or other undesirable compounds can build up in a deep bed of compacted botanical materials.

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 hydrogen sulfide or other nasty compounds 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 that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually 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. I could still be wrong.

There is so much we don't know about running our botanical-style aquariums in a variety of formats. The one thing that we DO know is that they require us to make a certain mental shift.

And managing a botanical-style aquarium system at it's most simple requires discipline.


Yeah, it IS cool to toss in leaves and seed pods and soil and such, and allow them to break down in an aquarium- but that doesn't lead to an easy path to success for some people. It's reproducible- but only to those who practice more careful, consistent husbandry, observation, and possess- or acquire- extreme patience.  

Only to those who put their faith in Nature and her smallest organisms, like bacteria, fungal growths, and biofilms.

"Shit, he's talking about mental shifts again!"

Yeah. Because they are so damn important to embrace. Especially if you really want keep things simple.

Remember, this is not an "aquascaping style." It's a methodology. An approach to running a more natural aquarium. It requires you to understand some natural processes and how they impact your little closed ecosystem.

So, while it seems like it would be nothing but fun to embrace the ultra simplicity of a minimally-equipped botanical-style aquarium, it's important to remember that experimentation on simple systems still requires us to engage with, and at least attempt to understand complex ideas.

Complex ideas run seemingly simple natural ecosystems.

We can return to simplicity- even while trying to recreate some of Nature's most elegant and complex habitats in our aquariums.

One of the things you notice in the images of many natural underwater habitats is that they're usually anything but squeaky-clean, filled with ultra-white sand and organized groups of plants, like we might imagine them in our tanks.

Rather, they're often sediment-filled, covered with stringy fungal growths, biofilms, and even a spot or two of algae. Plants, if present, are scattered where they find proper conditions. There is a fair amount of detritus accumulating in the substrate materials. And, as we have discussed relentlessly, detritus is not the enemy that we've made it out to be. Rather, it's a source of food for many aquatic animals, helping to literally "power" the ecosystem in which they are present.

This is something we can-and should- absolutely replicate in our aquariums. Don't be afraid of fungal growths, biofilms, sediments and even detritus accumulating on top of your leaves and's exactly what you see in Nature, and our fishes are ecologically adapted to such habitats.


And of course, the whole idea of a rich, sediment-sand-and-soil substrate enriched with decomposing 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, I believe that 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.

And it's important to allow Nature to plot the course.

This is contradictory to over a century of aquarium keeping methodology.

You, the aquarist, ever keen on anything that occurs in your tank, will notice- and often perform subtle (or not-so-subtle) interventions to counteract this process, lest it descend into some sort of chaos, right? 

Yet, isn't "chaos" sort of a human-ascribed thing?

I mean, we're talking about changes in the aquatic habitat which evolve the look and perhaps the biological "operating system" of the aquarium. This is absolutely analogous to what happens in natural aquatic systems.

Stuff breaks down, and different types of organisms flourish and reproduce as a result. Nothing goes to waste in Nature...and that includes the "nature" which is found in our aquariums, too..

If we allow it to happen.

Allow it to happen.

It's entirely possible, in my humble opinion, that we, as aquarists actually sabotage the essential natural processes which help our tanks run when we attempt to "intervene" through excessive maintenance.

Perhaps a sort of semi hands-off approach- "passive management", if you will- is not always a bad thing. And allowing Nature to work, unimpeded, as She has for eons, is always a good "approach."

The ultimate form of simplicity.

Stay thoughtful. Stay curious. Stay deducted. Stay observant...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Scott Fellman
Scott Fellman


3 Responses


July 14, 2021

OK! Thanks :)

Scott Fellman
Scott Fellman

July 12, 2021

Actually, this is a great question.

Personally, unless water testing is indicating a troubling trend (literally high nitrate or phosphate and accompanying issues like fish health or excessive algae) or problem (ie; nitrite or ammonia; fish gasping for air, etc),I’d just leave it “in play”, as it provides"fuel" for the organisms which comprise the microbiome of your aquarium. It’s really about monitoring, observing, and managing your tanks over time. If you continue to employ close observation, good husbandry, etc., Ipersoanlly don’t think you’ll have any issues. Hope this helps! -Scott


July 07, 2021

Nice :) That matter about surface area was part of my logic with my current ‘20H’ (which actually holds 15 gallons to allow space for a pothos plant on the right side of the tank) blackwater (the other part being to allow the stand to hold a 5 gallon spawning tank on the bottom shelf of the stand…it is not designed to hold much more than 20 gallons). I actually have a question to ask…is there ever a point where one would want to remove any of the leaves/detritus? My tank’s been set up over 2 months and has substantial biofilms and very good water parameters, I just wanted to check if it was possible for the leaf bed to get too deep (the tank has an air stone and an air powered box filter, so oxygenation is most likely not a problem).

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