I think about the idea of simplicity in our aquariums quite bit.
Not just the idea of less "gear", but a more simplistic means of operating an aquarium. Relying on Nature to do more of the work..Rather than trying to circumvent or skip processes altogether, I think that we can lean on Nature more than we have been doing in recent years.
We can return to simplicity- even while trying to recreate some of Nature's most elegant and complex habitats in our aquariums.
Now, sure, this is hardly a revolutionary concept. It's not some "new idea", of course. In the modern aquarium hobby's earliest days, filters and heaters were uncommon, if available at all, to most hobbyists. It really wasn't until the 20th century that such technological means to keep aquariums was commonplace. Of course, the simple reality was that most hobbyists relied more on the "balanced aquarium" concept.
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.”
Now, the whole idea of no water changes is, IMHO, an absurd exercise in laziness. Eventually, that kind of laissez faire approach will come back to bite you on the ass. So, that part of the "equation" is a big NO, IMHO.
I suppose a more modern definition of the idea of a "balanced aquarium" is an approach in which plants and animals interact within the confines of the aquarium to produce a stable environment. Okay, that was a really "weak sauce" definition by me, but 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.
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.
I think that is applicable to almost any type of aquarium, really.
Okay, let me just cut to the chase...
I think that the botanical-style aquarium can be run with a minimal amount of technical gear.
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 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.
Nothing we can tell you is an absolute guarantee of perfect results...You're dealing with natural materials, and 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.
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? 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?
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 a lot of 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 putter faith in Nature and her smallest organisms, like bacteria, fungal growths, and biofilms.
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 requires us to engage with, and at least attempt to understand complex ideas.
I personally think that's kind of fun!
Stay intrigued. Stay engaged. Stay excited. Stay curious...
And Stay Wet.