February 27, 2021

This is how I do it. Part I: Substrates.

Okay, this is likely the most literal title to any blog I've ver written. Yet, it occurred to me that in over 5 years of writing "The Tint" blog and doing the podcast, I've never had a piece about how I would start a botanical-style aquairum from scratch. If I had a dollar for every time I have been asked what my personal approach to this stuff is..well- you get the idea!

Now, look, there are as many ways to start the type of aquarium as there are aquarists, and I've varied my "techniques" over the years. The focus here will simply be on my fave way to start a botanical-syle aquairum; an approach that, despite all of my experimental "detours", I keep migrating back to again and again- because it works for ME.

This is not the "ultimate guide" to starting a botanical-style tank. The entire body of work on "The Tint" is your guide if you want it...And of my "life's work" on the topic, really, lol. Rather, this is a more concise bit on how I start most of my botanical-style aquairums. Not the more specialized "Urban Igapo" approach, or brackish, or any of the other weird ideas we toss around here...Just a good, "old-fashioned" botanical-style aquarium.

We could go into insane detail on every aspect of my approach- and likely have in the past, and will again- in this blog/podcast! Let's just keep it kind of concise and simple today! We'll start with soem of the components of a botanical-style tank and how I approach it.

Now, sure, because it's what I use, I might drop some "Tannin brand" products or mention various botanicals or leaves that we carry. Of course, you can collect your own stuff, or purchase from other vendors or guys on e-Bay or whatever (I mean, really...why would you? I give you the ideas- and they get your business? How DO you sleep at night?😆).

So, let's get to it.

First off, a word on tanks.

It starts with the type of aquarium you're using. Duh. I mean, You can use any sized tank you want. Lately, I've been relegated to "nano-sized" tanks (10 U.S. gallons or less) because of my home renovation, but typically, I like 40-50 gallon tanks when possible. I like the size, scale, and of course, the stability that they afford. But yeah- regardless of if you're starting with a 2-gallon tank or a 200-gallon tank, I'd recommend pretty much the same approach. Seriously.

My approach starts with the bottom. Literally. Let's go to that.

You have many ways to go when selecting substrates these days. The way I see it, you have four general choices:

"Traditional Sands": My go to's? I have a few...Fine white silica, CaribSea "Sunset Gold" or CaribSea "Crystal RIver", all of which mimic, in a very accurate manner, the look and texture of the substrates you see in many tropical aquatic ecosystems. They're clean, high quality substrates that can be used in all sorts of tanks.

I would certainly rinse these materials thoroughly, per the manufacturer's recommendations. No mystery there, right? And then, you simply add whatever botanical materials you want to use right on top.

"Sedimented Substrates": Yeah, that'd be ours. NatureBase "Igapo", "Varzea", and the upcoming "Mangal" are examples of substrates which have a lot of sediments and clays in their formulation. These substrates realistically replicate the composition, function, and look of soils which are found in many tropical aquatic habitats.

In fact, most of our NatureBase substrates have a significant percentage of clays and sediments in their formulations. These materials have typically been something that aquarists have avoided, because they will cloud the water for a while, and often impart a bit of color. Like, that's a problem? We also have some botanical components in a few of our substrates, because they are intended to be "terrestrial" substrates for a while before being flooded...and when this stuff is first wetted, some of it will float. And that means that you're going to have to net it out, or let your filter take it out.

You simply won't have that "issue" with your typical bag of aquarium sand!

You can mix them with any of the above-mentioned commercially-available sands, or use them alone. You can gradually add water (as in our "Urban Igapo" concept), or simply fill your tank form day one. Expect significant cloudiness for several days as the materials settle out, though. Don't rinse these substrates...just put them to work right away.

Now, although you can (and should) play with these substrates "wet" from the start, I'd be remiss if I didn't remind you again that the igapo and varzea substrates were initially intended to be "terrestrial" for a period of time, to get the grasses and plants going, and then inundated.

And of course, I'll advise you once again that immediately inundating a sediment-and-clay-heavy substrate can result in cloudiness. Just like in Nature. And it'll pass.

So, yeah, you'll have to make a mental shift to appreciate a different look and function. And many hobbyists simply can't handle that. We're being up front with this stuff, to ward off the, "I added NatureBase to my tank and it looks like a cloudy mess! This stuff is SHIT!" type of emails that inevitably come when people don't read up first before they purchase the stuff.

"Fusion Substrates": This is a fun approach, too! Mix crushed leaves, twigs, botanicals, "used" material from "Shade" "Substrato Fino" or "Fundo Tropical" with sand or NatureBase materials to create your own dynamic, botanical substrates.

The possibilities here are endless.

In my experience, and in the reported experiences from hundreds of aquarists who play with botanical materials breaking down in and on their aquariums' substrates, undetectable nitrate and phosphate levels are typical for this kind of system. When combined with good overall husbandry, it makes for incredibly stable systems.

I've been thinking through further refinements of the "deep botanical bed"/sand substrate relationship. I've been spending a lot of time researching natural aquatic systems and contemplating how we can translate some of this stuff into our closed system aquaria.

One of the most common questions we get about mixing stuff into the substrate is, "Doesn't this harbor dangerous hydrogen sulfide pockets when all of this stuff breaks down?"

Yeah, the big "bogeyman" that we all seem to zero in on in our "sum of all fears" scenarios is hydrogen sulfide, which results from bacterial breakdown of organic matter in the total absence of oxygen.

Let's think about this for just a second.

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 this reviled compound 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- and yeah, it IS just speculation- that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually be able to 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, sure, I'm not a scientist, and I base this on close visual inspection of numerous aquariums, and the basic chemical tests I've run on my systems under a variety of circumstances. As one who has made it a point to keep my botanical-style aquariums in operation for very extended time frames, I think this is significant. The "bad" side effects we're talking about should manifest over these longer time frames...and they just haven't.

So, yeah, I personally am totally okay with that stuff.

"Alternative Substrates": An even more fun approach! No sand or sedimented stuff for you- just add a layer of leaves, twigs, or crushed botanicals. That's your whole substrate. This is perhaps, one of the coolest approaches you can take. Over time, this stuff breaks down and becomes the perfect "microhabitat" for beneficial organisms, like crustaceans, fungal growth, worms, etc.

In other words, in a strictly aesthetic sense, the bottom itself becomes a big part of the aesthetic focus of the aquarium, with the botanicals placed upon the substrate- or, in some cases, becoming the substrate! These materials form an attractive, texturally varied "micro-scape" of their own, creating color, interest, and functions that we are just starting to appreciate.

In fact, I dare say that one of the next "frontiers" in our niche would be an aquarium which is just substrate materials, without any "vertical relief" provide by wood or rocks. I've executed many aquariums based on this idea (specifically, with leaves), and I've been extremely happy with their long-term performance! Oh, and they kind of looked cool, too...

Always remember, the substrate is not just a thing you toss on the bottom of the tank, or some strictly decorative product. Rather, it's a habitat- a place where the extraordinary organisms which comprise the microbiome of our aquariums reside and multiply.

Now, one thing that's unique about the botanical-style approach is that we tend to accept the idea of decomposing materials accumulating in and among the substrates within our aquariums. We understand that botanical materials in the substrate act, to a certain extent, as "fuel" for the micro and macrofauna which reside in the aquarium, and that they perform this function as long as they are present in the system.

So, yeah, in summary- the substrate plays a huge role in the function of a botanical-style aquarium. We can create a "facility" with substrate materials which provides not only unique aesthetics- it provides priceless benefits: Production of supplemental nutrition for our fishes, and nutrient processing via a self-generating population of creatures that compliment, indeed, create the biodiversity in our systems on a more-or-less continuous basis.

True "functional aesthetics!"

Consider that the next time you think of tossing some sand into your aquarium and calling it a day! Make mental shifts.

This is "how I do it!"

Remember, the substrate you select is not just a decoration. It's part of a living, breathing biome, which provides incalculable benefits to the entire aquarium. And it's every bit as compelling as any other aspect of our hobby- the we look at it this way!

We'll keep going with this periodic "How I do it" series...A lot to cover, I think!

Stay creative. stay curious. Stay thoughtful. Stay innovative. Stay observant...

And Stay Wet.

Scott Fellman

Tannin Aquatics