Pushing out further into the dark frontier...

With the growing interest in blackwater/botnaical-stye aquariums all over the world, we're seeing things happening on so many levels in so many areas of the hobby. Initially, virtually everything we collectively did was sort of "proof of concept" stuff; just seeing if we could throw leaves, seed pods, etc, into our aquariums and not have a disaster on our hands. Although hobbyists have been adding leaves and such to aquariums for years and years, it was always seen as sort of a "sideshow" and a kind of "anomaly" in the greater context of the aquarium hobby. Fear, rumor, misinformation, exaggerated claims, and simple disinterest dominated this topic.

It's all changing now. Rapidly. We as a whole are using blackwater aquariums to accomplish all sorts of cool things. And we're still learning. Learning to manage the chemical interactions and buildup of organics in a closed system, etc.

Nowadays, it's about refining techniques; using botanical materials to achieve specific goals, and using botanicals to create blackwater environments to accomplish things (both new and previously tried) that haven't been done before. We are literally scratching the surface of what is possible, and our knowledge, although expanding rapidly, is still very much in its infancy. 

What are some examples of concepts that are emerging as interesting places to play in the current blackwater "universe?" Well, let's take a look at some of the most exciting and promising avenues that hobbyists are taking as they push out into the "dark frontier!"

In no particular order...


Very low pH setups: This is currently the realm of super-experienced, highly experimental hobbyists, who are perhaps trying to unlock secrets of very demanding fishes, such as Altum Angels and others, which are known to come from and thrive in pH levels below 5.0. And, to achieve and maintain such pH levels, we're learning that the careful administration of acids is required. And the management of low pH systems, with the additional benefit of humic substances provided by botanicals, is a real "frontier" in the hobby. Even in the greater context of the blackwater aquarium world, it's seen as such. But it's not the frightening sideshow it once was.

Understanding water quality management and the way in which denitrification occurs in closed systems in very low pH is challenging. On the surface, it seems really scary. I believe it's more of a function of the fact that we haven't done much with this in the past, and we simply don't have a "path" to follow just yet. We need to understand a different class of organisms which "run the cycle" in this environment, and how to manage them. I suspect, that at some future point, there may indeed be more specific procedures, and perhaps even products available to manage the water quality, nitrogen cycle, and overall aquarium environment, It's a highly specialized area, but one which seem to be getting more and more attention from it's fans. We've seen hobbyists venture into "difficult and scary" hobby specialties before...Will this be the "reef aquarium" of the 2020's? We hope!




Planted blackwater systems: As more hobbyists are attracted to the aesthetics of blackwater aquariums, we're starting to pull in more and more aquascapers and planted tank enthusiasts. They're examining all sorts of ways to get plant growth in blackwater habitats. Now, it's long been known that many of the South American blackwater rivers, such as the Rio Negro, are essentially devoid of aquatic plants, or have extremely limited varieties of them. And I think that this might have discouraged a lot of aquatic plant enthusiasts from going further.

I've read a number of scientific papers which suggest that one of the largest factors limiting growth of aquatic plants in blackwater environments is...light penetration. Yeah, not pH, not lack of nutrients. Simple light penetration. And planted people know that you can obtain growth in aquatic plants through application of good lighting, CO2 administration, and rich substrates. We're starting to see all of these things being utilized on a more serious basis in blackwater, botanical-style aquariums, and the early results are that this is very promising! In fact, many have already been there, playing with plants like Cryptocoryne, which have long been known to thrive in various low-pH blackwater habitats. You can feel a "momentum" of sorts in this area that is exciting to see!


Fish breeding technique:  It's never been a "secret" that many fishes, such as Tetras, Bettas, killifishes, Rainbowfishes, Apistogramma, and many other fishes breed more ready and prolifically in blackwater systems. For decades, hobbyists have augmented or "conditioned" their fishes in aquariums in which leaves and peat and such were added to lower the pH and induce spawning. However, with the greater understanding and practice of keeping blackwater, botanical-style aquariums, we are seeing more and more "full-time" systems of this nature being utilized to keep fishes in for the expressed purpose of getting them to settle in and reproduce.

We're looking more and more at providing fishes with the conditions to which they have evolved over eons to live  and reproduce in on a full-time basis, rather than "adapting" them to our tapwater conditions. And since we've been doing this, we're seeing spawnings of fishes occurring o na very frequent basis. As techniques for maintaining such aquariums have evolved, I think that the mindset of many who's primary hobby is to breed certain fishes is evolving to. Perhaps we're seeing a greater acceleration of what already was an evolving "mental shift", letting go of some old preconceptions, and thinking about the long-term benefits of maintaining fishes full-time in blackwater conditions.



Rearing fry: With so many hobbyists who breed fishes  utilizing materials like leaf litter and various botanicals in their spawning setups, it is not surprising that we are beginning to see fry being reared in botanical-style aquariums as well. The presence of decomposing leaf litter and other botanical materials not only provides protection and foraging areas for fry, it's known to foster a variety of microbial life forms which provide them additional nutrition in their early life stages, much like they do in nature.

It's no just a longer a matter of these materials providing incidental beneficial microbial growth for fry which emerge in the spawning tank. Now, we know a number of breeders who are utilizing "deep leaf litter beds" in fry rearing tanks for fishes like Apistos and characins. Not only do the youngsters get the benefits of humic substances imparted by the leaves and such, they have a continuous safe foraging area. With some forethought, breeders might "inoculate" their rearing tank botanical beds with various beneficial microorganisms like Paramecium, rotifers, Daphnia, etc., to provide a full-time foraging substrate in the rearing tank! Interesting stuff that we're pretty excited to see more of! 


And to think, it all sort of started with hobbyists preparing and throwing some botanical materials in their tanks and realizing, "Yeah, this seems a lot like what we see in nature!"


Of course, there are many other areas in which you- the members of "Tint Nation"- are pushing the boundaries in aquarium technique by utilizing elements of blackwater, botnaical-style aquariums, and many more techniques to discover, develop, and refine. With so much interest in  our "dark world", we're seeing an exciting influx of new people, new energy, and new ideas, which will enrich and enhance the art and science of aquarium keeping, for the benefit of everyone who participates in this awesome hobby!

What interesting "specialty" are YOU working with in this context? What ideas are you trying to refine? 

Be sure to always share and discuss your findings- good and bad- so that we as a community can benefit and learn together!

Stay excited. Stay daring. Stay innovative. Stay engaged. Stay generous.

And Stay Wet.


Scott Fellman

Tannin Aquatics 



Scott Fellman
Scott Fellman


Leave a comment