Running "wild"- or just...running?

Today, wanted to get your thoughts on an idea that's been in my head for a while...

It's the idea of letting your blackwater, botanical-style aquarium "run on autopilot" just a bit.

What would happen?

We're all about diligent, thoughtful maintenance of our aquariums, right?

I mean, we spend a lot of time, money, and energy equipping our tanks with suitable gear, embracing excellent practices, and just stay on top of everything in general. Making sure that they run perfectly, and don't degenerate into some perceived "swamp" of death, lol.

So, what happens to our tanks if we sort of "let them go" just a bit? Especially, a botanical-style blackwater aquarium with a "deep leaf litter bed" or a significant assemblage of botanicals?Let's say that we stop doing weekly water exchanges and slip to say, once a month. Let's say all we're doing is topping off for evaporation during that time period, feeding fishes; that's about it.

What do you think will happen?

Will all of the botanical material continue to break down, keeping the water "tinted?" Will biofilms continue to colonize open surfaces? Will water chemistry swing wildly?  Will nitrate and phosphate rise off the charts? Will the aquarium descend into chaos? I mean, I think I have some opinions on the matter, based on a tank or two I let run like that in tests...and it was literally "no big deal."

Of course, that was me and two tests...

And you have to consider how these tank operate in general, right? I mean, when you think about it, the botanical-style blackwater aquarium is sort of set up to replicate a natural habitat where all of this stuff is taking place already. Decomposition, enrichment, nutrient import/export...

How much more will things change by simply delaying water exchanges for several weeks? Will nitrate and phosphate accumulate? Or, will the bacteria, fungal growths, and other microorganisms and crustacean life living in our botanical substrates continue to do what they do- breaking down organic waste and reproducing? Is a sort of "denitrification" taking place in the botanical bed you've created? 

I can't help but wonder if a botanical-style blackwater aquarium can better handle a period of "benign neglect" than many typical systems...Not that I'd want to do this, mind you... I'm a fairly diligent maintenance guy. I like my weekly water exchanges. But I can't help but wonder what happens in one of these systems if we let "nature take it's course" for a while? 

An interesting question...and perhaps an interesting experiment for the intrepid hobbyist. Don't ask me why this was on my mind this morning...

I open the discussion up to you.

Stay open-minded. Stay curious. Stay diligent. Stay ON it!

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


1 Response


January 14, 2018

I really like the idea of “benign neglect.” I try to allow my tanks to go their own way, when I can bear it. I recently ran an experiment with a 3 gallon aquarium in which I let it “go wild” for two months. I didn’t trim plants or change water other than to top off. At first it was great, lots of plant growth and all was well. Then something shifted, the guppy grass choked out every other plant and my shrimp and snails perished. I’ve since done a major trim down, and recovery has begun. I think the major factor was the size of the aquarium. The small volume of water was too restrictive to allow for change. Perhaps in a larger aquarium the results would have been different. I still think the goal of a healthy wild aquarium is a worthwhile one, and I’ll keep at it.

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