Challenge

Over the years here at Tannin, we've presented some of the work that we feel has pushed our hobby experience forward, challenged our skills, and questioned the status quo.

Here are a few ideas and their accompanying benefits that YOU can boldly run with and continue the work we started; take it to new levels and unlock some new secrets.

In no particular order:

LEAF LITTER ONLY (LLO) AQUARIUMS

Things to explore:  Supplemental/primary food production, denitrification/nutrient export, pH management, fish behavior and spawning, rearing of fry.

The idea here is really not all that complex! In fact, this approach is probably one of the easiest kinds of specialized tanks to create. You set up your aquarium with little to no substrate (if you're going to use substrate, we're talking 1/2"/1.27cm of sand), and add a layer of your fave leaves on top. We're talking anywhere from 1"/2.54cm- 6"/15.24cm deep.

And that's it.  Nothing else.

Oh, sure, you could toss a piece of wood in there if you need some "vertical relief" for your aesthetic sensibilities. It's not mandatory, of course. It's purely an aesthetic thing, or perhaps it's something you might want if you're keeping skittish fishes.

However, the main idea is to make the leaf litter the whole "scape"- the entire habitat within the aquarium.  In fact, it's less about the "look" than it is about the execution of a concept that can perhaps teach us a few things. By doing this, you're creating an aquarium which mimics the appearance and more important, much of the function of natural leaf litter habitats.

"Extra Credit"- Try "pre-stocking" your tank with organisms like Paramecium, Cyclops, Gammarus, Daphnia, and worms.

"URBAN IGAPO" (IGAPO/VARZEA SIMULATIONS)

Things to explore:  Seasonal wet/dry cycles and their influence on fishes, the relationship between terrestrial and aquatic habitats, substrate composition, marginal plant and grass growth, food production

The amazing habitat and it's seasonal inundation cycle has been begging to be replicated in the aquarium for decades. In 2018, I decided to go for it.

In many of the regions of Amazonia, for example-the water levels in the rivers rise significantly during the rainy season often several meters, and the once dry forest floor fills with water from the torrential rain and overflowing rivers and streams.

The Igapos are formed. 

Flooded forest floors.

The formerly terrestrial environment is transformed into an earthy, twisted, incredibly rich aquatic habitat, which fishes have evolved over eons to live in and utilize for food, protection, and spawning areas.

To replicate this process in the aquarium is really not difficult. It superficially mimics aspects of the "dry start" method that many aquatic plant enthusiasts play with. Except our goal isn't to start plants for a traditional aquarium. It's to replicate, on some levels, the year-round dynamic of the Amazonian forests.

It starts with a substrate which replicates the composition of the Igapo and Varzea soils of this region. (and yes, we offer them for sale...😆)

Add seed from terrestrial grasses to start the "cycle."

After a few weeks, the seeds should sprout. Once you have a nice growth of grasses, it's up to you as to when to bring on the inundation. At that point, just add water.

And of course, you can add fishes, too. I've experimented with small characins and annual South American killifishes! In fact, the concept lets itself very well to killies. When you're ready to bring on the "dry season again", you simply remove the water gradually. This replicates the desiccation which occurs as the rainy season fades. It's once again a terrestrial habitat.

In fact, in one of my "Varzea" simulations, I'm on my third generation of fishes derived from this wet/dry cycle! (Yes, I remove the adults when Im ready to drain the tank!) 

I am personally going to scale this up to a larger (50 US gal) tank soon. There's a lot to learn here. But you have to be really patient, accept some unusual aesthetics, and be willing to do things way differently than you have in the past. 

Things to explore:   Impact on pH, fostering biofilms and fungal growths,  supplemental "grazing" areas for fishes, spawning sites for cichlids and some characins, "nursery"  area for fry,  nutrient export processes.

they do in Nature.

The idea here is that the substrate becomes a dynamic part of the aquatic ecosystem. 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.

And the 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

Extra-credit- Another one to try pre-stocking with crustaceans and other microorganism cultures. A neat one to attempt spawning of egg-scattering fishes in...Will this matrix of material provide a "built-in" first food source for fry? Maybe?

Things to explore: Utilization of very rich substrate materials, decomposing leaf litter, live mangroves, simulation of food webs, alternative aesthetics.

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