The "Baseline..." and the inevitability of change in the botanical-style aquarium

As botanical-style aquariums "mature", it's obvious to all but the newest members of our community that the entire look of the tank will evolve and change over time. Leaves are shifted in the current. Seed pods become covered with biofilms and start breaking down, and the water darkens.


It's pretty much a given in the botanical-style aquarium world.

Yet, every tank sort of starts with a "baseline" look, right?

A sort of "default" set of aesthetics or parameters. In the case of most botanical-style tanks, we have a certain amount of hardscape: Driftwood, or maybe rocks, to sort of create the "framework" for the more malleable botanicals and leaves.

You can retain much of the "baseline" look by leaving the bulk of the botanicals in place, perhaps removing/replacing a few selected pieces from time to time. This gives you a sort of "established" look, and doesn't remove all of the "function", offering you a manageable option to keeping your aquarium more-or-less "fresh.

Or, you can simply allow much of the material to remain in play, and add new pieces as you see fit. A sort of actively-managed "evolutionary" process. One that not only mimics Nature in many respects (I mean, leaves and seed pods and stuff are constantly falling into, or being swept by currents into, aquatic habitats, right?), it will keep the microorganism/fungal/microcrustacean population aquarium biologically "fueled up", with a continuous supply of new food sources...just like in Nature!

The continuous replacement and supplementation of leaves and botanicals as they start to break down is a sort of process- okay, maybe even a habit- which many of us who play with botanical-style aquariums. This not only creates a continuously evolving aesthetic, it helps maintain the biological diversity and environmental parameters are held in the cherished "tight range".

Variation on a theme: I know a few "tinters" who make significant replacements of leaf and botanical items, taking out a lot of the older materials, while  replace them with fresh materials simultaneously, and this is conducted on a regular, although infrequent basis. This is similar to the Japanese aquascaping practice of "sozo haishoku" espoused by the late Takashi Amano, which is the processs of removing of as much old substrate material as possible along with the plants it contains in an aquarium, and replacing them with new materials.

It preserves the overall "composition" of the layout, but the "softscape" (the botanicals and leaves, in our case) could change dramatically over time. 

This process is very interesting to us as botanical-style aquarium fans, because, as we talked about many times before, it does sort of mimic what happens in many streams and rivers on a seasonal basis: Older materials are swept downstream as the watercourses swell, and are replaced by new ones that arrive to replace them.

And of course, in the aquarium, performing a "sozo haishoku"-type replacement of materials can significantly change the aesthetic of the aquascape because the botanicals are replaced with different ones after the previous ones are removed. It essentially means that your aquarium will significantly change over extended periods of time, likely bringing a very different look to the tank at different points in its operating "life cycle."

On the "downside" (there's always one, right?), it can also create significantly different environmental parameters when we do big "change-ups" of materials in a short span of time; the impacts on our fishes may be positive or negative, depending upon the conditions which existed prior to the move. 

Now, personally- I'm a fan of less "radical" moves, and in the interest of a good "offense", I favor regular, more measured additions to the botanical "set" in my aquariums. I tend not to remove any decomposing botanical material, unless it becomes an aesthetic detraction because it's blowing all over the place or something like that.

I while back, I did a slight "makeover" to my brackish water mangrove tank in my home office, which has accumulated a significant amount of decomposing mangrove leaf litter over the year-and-a-half that it has been in operation. I wanted to add a lighter-colored, fine sandy substrate to be more consistent with some of the brackish-water Mangrove habitats I've studied. So what did I do? Well, I literally placed the sand on top of the accumulated leaf litter detritus...

A pretty radical move for me!

And, quite honestly, it is a bit contrary to "standard" aquarium practice to pour new substrate material over decomposing materials. I mean, it impacts the biological processes occurring in the leaf litter.

And really, what happens is that, through the power of the current and the activities of my fishes, some of it rises up to the surface once again! And the water parameters have been unaffected by this move. With the understanding that we are attempting to foster multiple "levels" of life forms in our tanks, NOT removing all of the decomposing materials is a good move, IMHO. 

That was my "closest approach" to the process of "sozo haishoku", I think!

Think about food chains, microbial growth, and environmental stability in our aquariums. Fostering these requires us to embrace, rather than fear- some of these processes as they happen in our tanks. 

And of course, Nature provides examples of similar processes.

Of course, I have no illusions that open, natural aquatic systems operate differently from our aquariums, but the "concept" is essentially the same... Study this pic by our friend, Tai Strietman taken in the Amazon...Leaves being covered by sand...interesting! Nature provides a "prototype" for everything, huh? Nature's version of "sozo haishoku", I think.

Having studied many images of Amazonian igarapes, it is very obvious that, although some materials are swept away by currents, etc., many do remain in place until they fully decompose, adding to the richness and complexity of the habitat, and that we can mimic this process in our aquariums to some advantage.

And, when coupled with good husbandry technique (ie; water exchanges, population management, feeding, and use/replacement of chemical filtration media) an eye for aesthetics, patience, and a focus on creating as complete-functioning a microcosm as possible in our tanks, long-term success is virtually a given in botanical-style aquariums.

Okay, emphasis on "virtually." Nothing is a complete "given" in this hobby!

Now, far be it from me to say that one of these systems won't test your patience, diligence, and perseverance- but to those who do endure and hold steady, the rewards are there. Facing, accepting, and dealing with some of the early "aesthetic challenges" in botanical-style aquariums, like the appearance and proliferation of biofilms, fungal growth, and the breakdown of botanicals is a fundamental step in building our "skill set" in this speciality.

A mental shift.

And of course, you can take radically different starting approaches, as I've done recently- creating aquariums which "look" established right from the start, because you're immediately utilizing materials which foster rapid growth of biofilms, decompose quickly, and develop fungal/microbial populations more rapidly.

I have found this process, utilizing different combinations of soils and sediments, mixes of highly ephemeral and durable botanical materials, and a variety of wood and roots, to create some fascinating microcosms which mimic the wild aquatic habitats we love in a surprisingly realistic and highly functional manner.

And it's always changing.

As every botanical-style aquarist knows, it's simply a fact that terrestrial materials, which exposed to water, will decompose, recruit fungal and biofilm growths, and substantially impact the aquatic environment and the physical appearance of our tanks.

Exactly like in Nature!

I think it's very important to understand the reason why we create aquariums like this. What is the goal? What are we trying to accomplish? If we make an effort to understand the way the natural habitats we are enamored with truly function, it becomes way easier to manage them in a more confident manner.

Hobbyists unfamiliar with our processes and ideas will call this a mess.

We call it "natural."

I mean, when you think about it, the natural, botanical-style blackwater aquarium is sort of set up to replicate a habitat where all of this stuff is taking place already. Leaves, seed pods, etc. are more-or-less ephemeral in nature, and are constantly breaking down in these environments. Decomposition, accumulation of epiphytic growth, and colonization of various life forms is continuous.

There is a "baseline" of material which doesn't change all that much, forming the framework of you always-evolving system.

Understanding exactly what happens in these habitats is an amazing source of information which we can utilize to create truly amazing, highly functional botanical-style aquariums.

Stay focused. Stay curious. Stay diligent. Stay excited...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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