Gearing up. Or not. Equipping" the Botanical-Style Aquarium.

Today, I thought I'd switch things up a bit snd discuss the idea of...gear for your botanical-style aquariums. Specifically, the gear that I use and recommend to you. This will not be an authoritative review on every piece of equipment that you can use in the botanical-style aquarium, or a concise how to. Rather, it will be a simple discussion on the stuff that we use here for the many aquariums that we've played with over the years, why we selected the gear we use, and our thoughts on the various ones that we use.

First off, let's talk about aquariums.

I've used all sorts of tanks to create botanical-style aquariums over the years. You can use all sorts of tank shapes and sizes for botanical-style aquariums. I tend to favor wider, more shallow tanks for the aesthetics and for their surface area; however, you can use deeper, narrow tanks just as easily.

The biggie for me, however, is the so-called "all-in-one" (AIO) tank. These are simply aquariums which have a separate filter chamber located in the rear of the tank, which severs as a sort of sump- a location where the return pump. heater, and other gear (if you have it) can be placed. It's a real game changer, in MHO.

Most "all-in-one" tanks, like my Innovative Marine "Fusion Lagoon" system, or my Ultum Nature Systems AIOs, offer a great "hybrid" of a "sump" (in this case, a rear-mounted external filter compartment) and an external filter, making an affordable, simple, aesthetically clean, easy-to-maintain-and-operate system.

Now, I realize that not everyone wants the expense, logistics, challenges, and additional considerations (return pumps, space under the tank, etc.) which go along with the use of sumps. I also realize that the majority of freshwater hobbyists utilize glass aquariums without overflows and such, so there are numerous other options.

The other question that we receive all the time in regards to equipment is about filtration. Specifically, what filter to use.

of course you can employ those ubiquitous, ever-popular canister filters!


Shit, canister filters necessitate the need for...glassware, right? Arrghhhh.... 

IMHO, you should direct the return from canister filters near the surface, to create agitation and to facilitate gas exchange. Unlike pure planted aquariums, where there is a definite benefit from using those damn "Lily Pipes" and such to return water well below the surface to preserve CO2, I personally believe that heavily-stocked botanical-style aquariums benefit from this surface agitation.

Oh, did I mention that I hate those pipes? Just wanted to make sure on more time...

To be clear- I hate them...😆

And yeah, I've broken a bunch over the years...

You can return some of the water towards the lower levels of the tank to keep things "stirred up" just a bit, without blowing shit all over the tank. (that's a technical term, by the way).

And of course, outside power filters do the same thing- keep everything relatively neat and tidy, and potentially outside of the tank if you like.

Oh, and sponge filters are great- and those so-called "Matten Filters", too- because they are primarily biological filters and are relatively easy to hide in displays...

Now, I have spent a fair amount of time alleviating the fears of you weirdos who don't want to see leaves and pods and such in your tank physically by explaining that you can just toss these things into your filter or sump! And of course, it goes without saying that you can utilize all of these filters with the botanicals present in the display, as well, of course.

Like, duh.

Can you use chemical filtration media in a botanical-style tank?

Well, sure.

The real "issue", if you want to call it that- with filtration in regards to our botanical-style aquariums is what media you utilize. Again, I call on my reef-keeping experience to tell you that I am a huge fan of activated carbon. I use it on every tank I set up- even the ones with the gnarliest (yes, it's a word- I'm from L.A.-we talk that way. It's a word. Deal with it.), darkest "tint"  imaginable. 

I love activated carbon.


"Carbon? WTF Fellman?"

Yes, carbon can remove some of the tint and probably even some of the valued humic substances and other beneficial compounds exuded by botanicals. It's not selective. That being said, it also can remove impurities, like volatile dissolved organic compounds, urea, some metals, etc. It's valuable stuff.

The key is to just not overdo it.

Of course, if you want leaves and such in your tank, but not the tint- as we've discussed many times- just use the 'recommendedl" dose of carbon and you have the best of both worlds- at least, aesthetically.

Better as chemical filtration media would be stuff like specialized ion-exchnage or "organic scavenger resins" and zeolites- stuff which requires more research, trial and error, and testing. But it is possible, at least in theory, to incorporate filtration media which removes the undesirable pollutants and retains the desired humic substances and tannins. Oh, and proper biological function in low pH systems, fostering the "biome" of these tanks.

I like the"Poly Filter" pad, by Poly BioMarine, as it removes organics and can remove stuff like ammonia even in low pH systems. In my years of working with this stuff, I have not seen it remove substantial amounts of the "tint" in the water caused by tannins from botanicals. This is hardly a scientific assessment of the stuff, but I believe in it. I've used it for decades in pretty much every type of aquarium- fresh, brackish, reef- that I've maintained with excellent results. 

And back to those "specialized resins" and such...

These things are are all something we will see more of in the me. There are numerous materials out there, used in other water purification work , that will definitely work with our aquariums.

In the mean time, you can continue use materials like carbon, Purigen, etc. to do the trick; just be aware of the way they work and what they will do. If you go "full power" (ie; the typical manufacturers' recommended "dose"), you'll have a really clear tank- if that's what you want.

Nonetheless, I adore Seachem Purigen.

It's a "macro-porous synthetic polymer" (aka "organic scavenging resin") that removes soluble and insoluble impurities from water by adsorption. In other words, it cleans up stuff.

Like, really well.

More filtration ideas for botanical-style aquariums? 

Well, you could actually use the tank itself, and the botanical environment as the "biological filter", and simply use aeration/surface skimming and/or circulation pumps to facilitate the gas exchange. Not revolutionary, of course- but an idea that's often overlooked today.


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.

Oh, the part about the biofilms and fungal growths sounds familiar, doesn't it?

Let's talk about our buddies, the biofilms, just a bit more. One more time. Because nothing seems as contrary to many hobbyists than to sing the praises of these gooey-looking strands of bacterial goodness!

Structurally, biofilms are surprisingly strong structures, which offer their colonial members "on-board" nutritional sources, exchange of metabolites, protection, and cellular communication. They form extremely rapidly on just about any hard surface that is submerged in water.

When I see aquarium work in which biofilms are considered a "nuisance", and suggestions that it can be eliminated by "reducing nutrients" in the aquarium, I usually cringe. Mainly, because no matter what you do, biofilms are ubiquitous, and always present in our aquariums. We may not see the famous long, stringy "snot" of our nightmares, but the reality is that they're present in our tanks regardless.

The other reality is that biofilms are something that we as aquarists typically fear because of the way they look. In and of themselves, biofilms are not harmful to our fishes. They function not only as a means to sequester and process nutrients ( a natural "filter" of sorts?), they also represent a beneficial food source for fishes.

Now, look, I can see rare scenarios where massive amounts of biofilms (relative to the water volume of the aquarium) can consume significant quantities of oxygen and be problematic for the fishes which reside in your tank. These explosions in biofilm growth are usually the result of adding too much botanical material too quickly to the aquarium. They're excaserbated by insufficient oxygenation/circulation within the aquarium.

These are very unusual circumstances, resulting from a combination of missteps by the aquarist.

Typically, however, biofilms are far more beneficial that they are even remotely detrimental to our aquariums.

Yeah, they're really quite useful as a form of biological filtration.

Nutrients in the water column, even when in low concentrations, are delivered to the biofilm through the complex system of water channels, where they are adsorbed into the biofilm matrix, where they become available to the individual cells.  Some biologists feel that this efficient method of gathering energy might be a major evolutionary advantage for biofilms which live in particularly in turbulent ecosystems, like streams, (or aquariums, right?) with significant flow, where nutrient concentrations are typically lower and quite widely dispersed.

Biofilms have been used successfully in water/wastewater treatment for well over 100 years! In such filtration systems the filter medium (typically, sand) offers a tremendous amount of surface area for the microbes to attach to, and to feed upon the organic material in the water being treated. The formation of biofilms upon the "media" consume the undesirable organics in the water, effectively "filtering" it!

Biofilm acts as an adsorbent layer, in which organic materials and other nutrients are concentrated from the water column. As you might suspect, higher nutrient concentrations tend to produce biofilms that are thicker and denser than those grown in low nutrient concentrations.

Those biofilms which grow in higher flow environments, like streams, rivers, or areas exposed to wave action, tend to be denser in their morphology. These biofilms tend to form long, stringy filaments or "streamers",which point in the direction of the flow. These biofilms are characterized by characteristic known as  "viscoelasticity."This means that they are flexible, and stretch out significantly in higher flow rate environments, and contract once again when the velocity of the flow is reduced.

Okay, that's probably way more than you want to know about the physiology of biofilms! Regardless, it's important for us as botanical-style aquarists to have at least a rudimentary understanding of these often misunderstood, incredibly useful, and entirely under-appreciated life forms.

And the whole idea of facilitating a microbiome in our aquariums is predicated upon supplying a quantity of botanical materials- specifically, 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.).

Oh, I'm going on and on about this stuff- but the idea of the aquarium, or more precisely, the microbiome of the aquarium- acting as a "filter"- is worth considering. You could successfully run a botanical-style aquarium without a "filter" of any kind, other than the materials contained within the tank itself. 

I mean, this isn't really an earth-shattering concept. Every tank in the 19th century, and many in the early 20th century, ran this way, right? Yeah. Now, I get it- these were plants which were often dominated by aquatic plants, which processed the nutrients and realized oxygen via photosynthesis, but the idea here is essentially the same- creating a biological system which assimilates and processes nutrients.Our "Urban Igapo" tanks use terrestrial or riparian plants...they uptake nutrients from the soils...

Yet, there are other organisms besides plants to accomplish nutrient export, right? Now, what about our old nemesis, cyanobacteria- that stringy stuff we've been taught to loathe over the years? Well, they're photosynthetic. They convert sunlight into energy and produce oxygen as a waste product. Maybe cultivating them in our "filterless" tanks could be a cool idea, huh?


Well, I'm getting sidetracked a bit, but it's interesting stuff, right? 

The point is, botanical-style aquariums can be managed in a great variety of ways.  You can go with high-tech filtration, simple old-fashioned filters, just an airstone, or, no filter at all.  (which is to say, no additional mechanical equipment...).

There are so many possibilities here, huh? 

Stay open-minded. Stay thoughtful. Stay creative. Stay curious...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



Scott Fellman
Scott Fellman


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