When it comes to working with the botanical method, you find yourself embracing some weird stuff...I mean, I suppose that to many, the very idea of adding a whole bunch of leaves and seed pods and stuff to an aquarium seems decidedly strange, doesn't it?
That being said, it's one of the easiest approaches to aquairum keeping that I've worked with in my life. The most difficult part? Letting go of everything that you've been told an aquarium should be!
What would be the easiest botanical-method aquarium to set up and maintain, in my opinion? My answer might surprise you, but I think that an aquarium based primarily on leaf litter would be among the best ways to introduce yourself to this approach. Coincidentally, leaf litter beds are pretty much one of the main types of ecological niches that we obsess over.
Leaf litter in an aquarium gives you the whole range of botanical method aquarium experiences: Preparation of the materials, adding them into the tank, watching early colonization by fungal growths and biofilms, and ultimately, the decomposition of the leaves.
Yeah, the whole smack!
Nature provides no shortage of inspiration and habitat examples. In many aquatic habitats, you'll find significant litter banks. Now, in our blackwater/botanical-method aquariums, we often include leaves as part of the display. However, I can't say I've seen all that many aquariums which have their aquascape composed exclusively of leaves! In other words, a tank which attempts to simulate a leaf litter bank itself as the overall "theme."
Seriously, it seems kind of funny, given all of our talk about them, but yeah, I can't recall too many tanks which are simply a fine, sand substrate, and leaf litter- with nothing else.
As I mentioned previously, the thing that I really love about running a leaf litter-focused aquarium is that it teaches you all of the principles of the botanical-method aquarium approach. You'll learn about preparation of botanicals, and how to add them to an aquarium. You'll also get to see firsthand how an aquarium develops as an ecological system. You'll learn the valuable skills of replenishing and maintaining a botanical-heavy system. You'll witness fungal colonization, biofilms, and decomposition.
And most important of all- you'll learn to enjoy watching your aquarium evolve at every stage. You'll learn that things don't happen quickly. You'll prefect the art of patience.
Talk about an "ephemeral" habitat- a tank with the "hardscape" composed entirely of leaf litter would be just that: Constantly evolving and changing. It would be a tank that you would most definitely have to "actively manage", in the sense that you'd be replacing leaves on a frequent basis as they break down- a process which, as we've stated many times- mimics what occurs in Nature.
And of course, being a fish geek, you'll need to deploy a healthy sense of discipline to not want to "supplement" the "litter bank" with other botanicals, or throw in a big old piece of driftwood or whatever. Yup, we're talking about just modeling our system after the main leaf litter bed itself. Maybe a few small twigs or branches, but nothing resembling a conventional aquarium hardscape.
So the execution of this type of setup is really pretty easy. In fact, I'm almost embarrassed to write these "instructions": Prepare your leaves and add them to the already-filled aquarium.
Like, seriously. There isn't all that much to the process.
Okay, a few pointers...
I like utilizing the tiniest amount of substrate. I suggest starting off with a mere sprinkling of sand or other substrate materials (like maybe 1/2 inch /1.27cm or less), to create a literal "foundation", and perhaps to provide an additional layer for organisms which thrive in the substrate to "work" the leaves and assimilate the resulting detritus as they decompose.
From there, you add your leaves. You can simply use one leaf type, or a multiple of leaf types if that appeals to you. If you;'re using different types, it would make sense to start with your most "durable" leaves (examples would be Live Oak, Magnolia, or Yellow Mangrove) as the "first layer" of the litter bed, as the "structural integrity" they provide would create some void spaces and a "trophic structure" (a structure that fosters the feeding habits or relationships of different organisms in a food chain or food web).
This would also allow some water circulation within the litter bed itself, to avoid the possibility of creating small, anaerobic pockets as the leaves break down. (FYI I've never had this happen in over 17 years of playing with leaf litter only setup, but I'd be remiss if I didn't at least mention the possibility...)
Once your leaves are down, there is really not much you need to do.
The real keys are to prepare your leaves well by boiling or long-term steeping, so that they'll sink easily, and to not direct filter returns or pump returns right into your leaf litter bed- otherwise you'll have a continuous "leaf tornado" forever.
Oh, and the question I receive a lot is, "What kind of filter should I use on this type of tank?"
It's a good one...You can use pretty much any filter available.
The key is to not suck up leaves in the process, and to not direct the water returns into the litter bed as I just mentioned. Personally, I've used everything from outside power filters to canister filters, to sponge filters, to small internal filters...and even NO filters! Everything worked! The key is to simply go slowly and use common sense when adding your fishes to the aquairum.
I would definitely try to agitate the surface a bit, simply to facilitate gas exchange. Oh, I've even used simply one of those "surface skimmers" as the sole "filtration" in a leaf litter tank and it was just fine.
I do recommend at this point that you add some bacterial additives- either one of the many nitrifying bacterial supplements available, or our own Purple Non- Sulphur bacterial additive, "Culture." Bacteria are your first line of defense; they assist in the breakdown of organics leached by the leaves.
The real key- like it is to any botanical-method aquarium- is to deploy patience and go really slowly, allowing the aquarium to run in at it's own pace. Don't get hung up on the aquarium's appearance at its earliest phases. As the materials begin to be colonized by microorganisms and fungi, they begin to soften, the water begins to clear, and the ecological processes of the aquarium get underway.
Now, one caveat:
To create a leaf-litter-centric aquarium, you need a lot of leaves, right? And, with a large volume of leaves added to the aquarium from day one, you would not want to convert an existing system with a population of fishes to such a tank quickly. The potential exists for some big problems if you attempt this: Excessive bacterial respiration as a result of a large influx of leaves to an established system could lower the water's dissolved oxygen AND increase CO2...a recipe for disaster with an existing fish population.
So, if you're wanting to convert an existing aquarium to a leaf-litter-focused one, the key is to go very slowly and to add the leaves over time.
Never forget this, though:
The aquarium-or, more specifically- the botanical materials which comprise the botanical-method aquarium "infrastructure" acts as a biological "filter system."
In other words, the botanical materials present in our systems provide enormous surface area upon which beneficial bacterial biofilms and fungal growths can colonize. These life forms utilize the organic compounds present in the water as a nutritional source.
And the whole idea of facilitating a microbiome in our aquariums is predicated upon supplying a quantity of botanical materials- in this case, leaf litter, for the beneficial organisms to colonize and begin the decomposition process. An interesting study I found by Mehering, et. al (2014) on the nutrient sequestration caused by leaf litter yielded this interesting little passage:
"During leaf litter decomposition, microbial biomass and accumulated inorganic materials immobilize and retain nutrients, and therefore, both biotic and abiotic drivers may influence detrital nutrient content."
The study determined that leaves such as oak "immobilized" nitrogen. Generally thinking, it is thought that leaf litter acts as a "sink" for nutrients over time in aquatic ecosystems.
Oh, and one more thing about leaves and their resulting detritus in tropical streams: Ecologists strongly believe that microbial colonized detritus is a more palatable and nutritious food source for detritivores than uncolonized dead leaves. The microbial growth which occurs on the leaves and their resulting detritus increases the nutritional quality of leaf detritus, because the microbial biomass on the leaves is more digestible than the leaves themselves (because of lignin, etc.).
Okay, great. I've just talked about decomposing leaves and stuff for like the 11,000th time in "The Tint"; so...where does this leave us, in terms of how we want to run our aquariums?
1) Add a significant amount of leaf litter to your aquarium as the primary component of the physical structure in the aquarium.
2) Inoculate the aquarium with bacterial and/or other microorganism/crustacean cultures.
3) Allow biofilms and fungal growths to proliferate.
4) Feed your fishes well. It's actually "feeding the aquarium!"
5) Don't go crazy siphoning out every bit of detritus. In fact, if you can handle it, just forgo the siphoning altogether- at least for a while.
I'd be remiss if I didn't at least touch on the idea of feeding your leaf-litter aquarium. Think about it: When you feed your fishes, you are effectively feeding all of the other life forms which comprise this microbiome. You're "feeding the aquarium." When fishes consume and eliminate the food, they're releasing not only dissolved organic wastes, but fecal materials, which are likely not fully digested.
The nutritional value of partially digested food cannot be understated. Many of the organisms which live within the leaf litter bed and the resulting detritus will assimilate them.
Our aquariums- just like the wild habitats they represent-are not spotless environments, and that they depend on multiple inputs of food, to feed the biome at all levels. This means that scrubbing the living shit (literally) out of our aquariums is denying the very biotia which provide our aquariums with their most basic needs!
That little "unlock" changes everything, once you embrace it.
Suddenly, it all makes sense.
This idea has carried over into the botanical-method aquarium concept: It's a system that literally relies on the biological material present in the system to facilitate food production, nutrient assimilation, and reproduction of life forms at various trophic levels.
It's changed everything about how I look at aquarium management and the creation of functional closed aquatic ecosystems.
It's really put the word "natural" back into the aquarium-keeping parlance for me. The idea of creating a multi-tiered ecosystem, which provides a lot of the requirements needed to operate successfully with just a few basic maintenance practices, the passage of time, a lot of patience, and careful observation- is something that has been discussed, but rarely executed in the hobby.
It means adopting a different outlook, accepting a different, yet very beautiful aesthetic. It's about listening to Nature instead of the dude on Instagram with the flashy, gadget-driven tank. It's not always fun at first for some, and it initially seems like you're somehow doing things wrong.
Executing this is about as easy as aquarium-keeping gets.
The difficult part is understanding that this is an extremely natural, ecologically beneficial process, and that it facilitates the appearance of some things that you might not be comfortable with initially (like, cloudy water, fungal threads, biofilms, decomposition...all that stuff!). Making those mental shifts to accept something different than what the aquarium hobby establishment has proffered as the way to go for generations.
You have to give things time to establish and settle.
It's about patience.
It's about faith.
Faith in Mother Nature, who's been doing this stuff for eons. Faith that you're doing something which embraces Nature's processes so fully.
It's about nuance.
It's about not being afraid to question the reasons why we do things a certain way in the hobby, and to seek ways to evolve and change practices for the benefits of our fishes.
It takes time to grasp this stuff. However, as with so many things that we talk about here, it's not revolutionary...it's simply an evolution in thinking about how we conceive, set up, and manage our aquariums.
Our botanical-method aquariums are not "set-and-forget" systems, and require basic maintenance (water exchanges, regular water testing, filter media replacement/cleaning), like any other aquarium. They do have one unique "requirement" as part of their ongoing maintenance which other types of aquariums seem to not have:
The "topping off" of botanical materials as as they break down.
It's a regular thing; almost a revered, ritualistic sort of thing among us hardcore botanical-method aquarium freaks.
The "topping off" of leaves in your tank accomplishes a number of things: first, it creates a certain degree of environmental continuity- keeping things consistent from a "botanical capacity" standpoint. Over time, you have the opportunity to establish a "baseline" of water parameters, knowing how many of what to add to keep things more-or-less consistent, which could make the regular "topping off" of botanicals a bit more of a "science" in addition to an "art."
At the most superficial level, regularly topping off your botanical materials keeps a consistent aesthetic "vibe" in your aquarium. Consistent, in that you can keep the sort of "look" you have, while making subtle- or even less-than-subtle "enhancements" as desired.
And, when you think about it, this replicates the processes which happen in Nature, when materials are continuously washed into streams or other bodies of water, accumulating in the aquatic ecosystem.
So, yes, we've kind of come full circle in this little piece. Not only did we discuss the whole idea of creating a leaf litter-focused aquarium, we sort of re-visited the fundamentals of the botanical-method aquarium approach itself, and how it very effectively replicates the way many natural aquatic ecosystems function.
I hope that it's encouraged YOU to attempt to create a simple, leaf-litter-focused aquarium system of your own. As we've discussed, it will give you a perfect encapsulation of all of the things which make the botanical-method of aquarium keeping so engaging, educational, and fun!
Stay engaged. Stay studious. Stay creative. Stay observant. Stay bold. Stay excited...
And Stay Wet.