The Benefits of Disruption?

Throughout my tropical fish hobby "career", I've praised the concept of stability in my aquarium work. I have long valued the idea of stable environmental conditions, long-term management, and minimal disruption of my aquariums. Indeed, it has served me- and my fishes-well.

However, in the past couple of years, as I relocated to my new home and had to create temporary aquariums for some of my fishes while renovating the new home, I began to notice how easily my fishes seemed to take all this disruption. In fact, far better than I have!


And in studying many of the natural habitats which I find so compelling, it turns out that fishes have to deal with a significant amount of disruption as part of their life cycle. In fact, in some instances, it's not just something that the fishes have to "deal with"- it's something that they have evolved to work with!

In Nature, fishes will frequently migrate into and out of areas as the seasons change. Often, this is because they are following food sources, shelter, and stability. Instinctive urges to feed, reproduce, and flee predation compel fishes to move from environment to environment. Other fishes, like annual killifishes, essentially require these "disruptions" in order to complete their life cycle.

Their reproductive strategy involves laying their eggs in the substrate, which provides the correct conditions to incubate as the pools they live in dry out. The eggs develop in the dry ground, awaiting the next rainy season to hatch and continue the cycle of life.

This ability of fishes to deal with environmental disruption is a profound adaptation, and one which we as aquarists, with few exceptions (like breeding annual killies, for example)  have likely not intentionally leveraged to our advantage over the decades of the modern aquarium hobby.

I think that while my "stability obsession" over the years has been good for my fishes, I believe that this may not be the very best way to keep many fishes in all instances. I think that there are options which we can employ to do things better. I think we can manage our aquariums more "realistically."

I believe that our fishes can benefit from us offering some "disruption" or changes to their environment from time to time. I believe that many of them are genetically or instinctively "programmed" to endure- and even to benefit from -such environmental changes as part of their life cycles. I base this on the many well-known adaptations that fishes have had to make to cope with the changes that regularly occur in their environments.

I realize that this is somewhat contrarian to the long-accepted aquarium standard of stability in every way, and it's something I've had to re-visit myself over the years...I mean, I've traditionally been the type of aquarist who adopts a sort of "hands-off" stance when it comes to "messing" with my tanks once they're up and running. I still tend not to "mess with" my systems all that much once they're up and running. Yet when managing systems like the "Urban Igapo" tanks I love, I've noticed interesting positives in the health of my fishes. 

However, when we consider the way Nature functions when She impacts aquatic ecosystems, there is something there, I think. In the wild, many fishes are subjected to such environmental fluctuations and disruptions to their physical environment on an almost semi-regular basis.  

They seem to do just fine. I think that any stress which fishes may accrue as a result of temporary disruption is far, far different- and less deleterious- than continuous stresses (environmental, etc.) endured by our fishes.

In fact, we've embraced some aspects of this type of environmental manipulation with fish breeding techniques for many years: Lowering water temperatures to mimic rainstorms for Corydoras, or exhaling into a test tube of water containing annual killifish eggs to add CO2 to the water to stimulate hatching, etc. Practices which represent environmental changes- disruptions- brought about by rapid, short-term meteorological conditions.


Think about that for a minute.

I would imagine that there are a lot of benefits to be realized by "deconstructing" and replicating the processes of disruption and change which Nature imparts to our fishes environments.  We could gain a lot as hobbyists from simply studying and considering how fishes react to the environmental disruptions and changes that they face in Nature.

Think about the way fishes adapt their behaviors and strategies to feed in the wild...It might give us some interesting insights that we can apply to aquarium work.

For example, as we all know, in Nature, fishes spend a significant amount of time and energy searching for food.

On the Amazonian floodplains, for example, the flood cycle of the rivers into the igapo are the dominant seasonal factor, and fish communities are found to fluctuate greatly over the year. During inundation, fishes migrate into floodplain forests to feed on insects, fruits and seeds, among other things.

Studies of blackwater communities showed that, during these cycles, a greater diversity of fishes exists there. Many species were found to be specialized feeders. Fish, detritus and insects were the most important food resources supporting the fish community in both high and low water seasons, but the proportions of fruits, invertebrates and fish were reduced during the low water season.

In other words, they adapt to the availability of different food sources at different times of the year by adjusting their dietary preferences.

Are there some "takeaways" here for us fish geeks?


Perhaps we could simply alter the stuff we feed our fishes at different times of the year! In other words, feed a correspondingly more frequent, more intensive diet of say, worms, fruit flies, or Daphnia in a period of time that corresponds with the wet season?

And then, perhaps reducing frequency, quantity, and variety of foods at other times- perhaps even doing a several week-long "hiatus" or two, to encourage them to forage on the biocover and natural foods you have encouraged to accumulate within the aquarium?

That's one change-or-"disruption" that we could relatively easily recreate in the aquarium. I've done this a number of times over the years with tremendous success. It all revolves around how we set up our systems for this sort of operation.

My extensive experiments with leaf-litter-only systems and the natural detritus, fungal growths, and biofilms that they accumulate have demonstrated that some fish can not only adjust their feeding preferences in aquariums, but that they can thrive on various natural foods.

Simply adjusting foods on a seasonal basis to mimic the changes which fishes encounter in the wild could possibly trigger some sort of physiological responses within their bodies which may create greater vigor, better colors, and perhaps even foster spawning behaviors.

And then there is the "Urban Igapo" idea which we've been discussing a lot lately. The concept of recreating the seasonal wet/dry cycle of some tropical environments in our aquariums is fundamentally different than anything we've played with before. Yes, it's a rather extreme, very dynamic process, but it's already given us some interesting insights into the wild habitats of our fishes and how they change over time.

Disruption, in our case, isn't always about disrupting the aquarium and it's function. It's also about the disruption of a prevailing hobby mindset which suggests that Nature is a pristine, orderly place, and that our aquariums should reflect this. Sometimes, shaking the status quo of aquarium "religion" is a good forces us to think, and to not continuously mis-appropriate terms like "Natural" in the hobby.

The botanical-style aquarium itself is an example of this "disruption."

Or, "counter-disruption!" 


Think about this: We spend a lot of time trying to "polish" out things which we don't feel (for largely aesthetic or philosophical reasons) belong in our aquariums. In the interest of "management" of the aquarium, we end up disrupting biological processes and systems by excessively removing stuff like detritus, biofilms, and fungal growths. Things which are not only essential parts of the ecosystem- they are food for a myriad of life forms throughout the "biome" of the aquarium.

Accepting that the aquarium habitat evolves over time if we - transformed by unstoppable, constant natural processes is hugely important and transformative. These processes often result in aquarium habitats which look-and function just like they do in Nature.

And I understand that not everyone can handle that.

I admit, I feel a bit sorry for these people who can't make the "mental shift" to accept the fact that Nature does her own thing, and will lay down a "patina" on our botanicals, gradually transforming them into something a bit different than when we started. When we don't accept this process, we sadly get to miss out on Nature guiding our tank towards its ultimate beauty- perhaps better than we even envisioned.

For some, it's really hard to accept this process. To let go of everything they've known before in the hobby. To NOT disrupt what is occurring in their tanks. To wait while Nature goes through her growing pains, decomposing, transforming and yeah- evolving our aquascapes from carefully-planned "art installations" to living, breathing, functioning microcosms.

But, what about all of that decay? That "patina" of biofilm?

It's okay.

It's normal.

Their presence "waxes and wanes" to a certain extent- the product of a botanical bioload. Yet they're always there, as they are in natural habitats. And making the effort to understand and even appreciate their appearance as a sign that your aquarium is functioning as Nature intended is the biggest step in achieving what can only be called a form of "aquatic enlightenment." 

The accumulation of materials- dissolved substrate constituents, decomposing leaves and botanicals, bits of biofilms and fungal threads- is fundamental to the ecology of our aquariums.

It's part of this type of approach. It's present in all natural aquatic systems. We just work with it instead of against it. To NOT disrupt it. Instead of trying to sanitize, edit, or otherwise "redirect" Nature, we understand that it will follow its own path, sometimes going through phases that we may not appreciate.

And guess what? It never stops.

You wouldn't want it to.

The ebb and flow of life in a natural, botanical-style aquarium is much like a garden. You can and should perform regular maintenance, conducting water exchanges, filter media replacement, etc.- like you do in any other tank. However, you need to conduct these maintenance sessions not with the idea of "THIS will take care of those biofilms", but an attitude of, "This will continue to facilitate change over time..."

Yeah, it requires a certain attitude.

And a willingness to look at Nature as she actually is- and to appreciate the beauty in the details of her processes. Letting decomposing materials remain in the system to fuel the ecology.

So, on a practical, functional level, is there an issue in allowing these materials to accumulate?

Of course not.

We know this, because our aquariums are essentially configured to use decomposing botanical materials as the "operating system." Those who try botanical-style aquariums simply for the unique aesthetics will, sadly, never fully realize the benefits of creating an ecology around the botanicals. That's why it's so important to have an open mind and a desire to learn about developing an ecosystem, not just a cool aesthetic.

I think that, in general, we get a bit too obsessed about avoiding any type of disruption in our aquairums.

I'm also convinced that sometimes, as hobbyists, we tend to get a bit- well, "overly concerned" about stuff that non-hobbyists don't understand? Or, perhaps they do-more than we can comprehend- and will occasionally come up with some "pearls of wisdom" that blow us away!


Case in point:

Not long ago, I recall walking into my office early one morning, and I immediately was taken aback. Someone had apparently left one of the computers in the office on all night, and the room was fairly brightly illuminated. No biggie, except for the fact that one of my office aquariums, the South-igarape-inspired leaf litter tank that you've see so much on these pages, resided there, too, and I recently added some cool wild fishes to the tank, acclimated and carefully quarantined...and then- THIS had to happen, know where I'm going with this?

This was going through my mind:

"Omigod, the fishes didn't get any dark period...they've been seriously stressed..."

You will say that this wouldn't bother you- but you're totally lying! It would bother the shit out of you, too! I know it would, 'cause you're a fish geek. It's part of what we do.

Of course, I relayed this concern to my wife later in the day, when we touched base and asked each other how are days were progressing.

To which my wife, who is not a fish geek, yet ever the pragmatist, noted, "You know, it's not that big a deal. Sometimes, unexpected things happen in the Amazon."


She was on to something there! Yeah, That was right.

And it's not just me who freaks out about stuff like this. I know for a fact...

It's a fish-geek thing.

I think, that as hobbyists, we tend to get caught up in every little minute detail of the little worlds we've created for our fishes- so much so that we often forget the one underlying truth about them: They're living creatures, which have evolved over eons to adapt to and deal with changes in their environment-big and small...or even insignificant, like an excessive amount of light one evening. 

They CAN handle disruption.

I mean, there must have been some natural precedent for this, right? Some atmospheric phenomenon- or combination of phenomenon-which rendered the night sky inordinately bright one evening at some point in the long history of the world?

And, all of the fishes lived, right?

Yeah. Exactly.

Disruption can be upsetting...but likely more upsetting to us than to the fishes. They do what they've always done- they find a way to adapt. To thrive. And even spawn. Again, one need only think of the temperature drop and large water-exchanges which hobbyists execute to breed fishes like Cories and others. It triggers something in the fishes, doesn't it? These "disruptions" don't harm them, right?

Now sure, constant disruption is a recipe for stress...which is a condition that allows for disease to arise. I get that. And a major environmental fluctiation- like a sudden decrease in dissolved oxygen or a huge drop in pH- can be fatal. However, the occasional disruptive event, like tearing up the hardscape, removing plants, adding substrate, sending detritus into suspension, etc. is, in my humble opinion, probably rather more beneficial for the fishes in the grand scheme of things than it is detrimental.

It's surprisingly natural, actually.

I kind of feel that it keeps them reacting to stimuli the way that they have for untold millennia, right? 

I think so.

So, the next time you're a bit concerned because you felt that your 50% water exchange was a bit too aggressive, just consider what happens in the wild streams, ponds, and forests in Nature where fishes have lived- and thrived- for eons. And realize that, in many cases, the fishes will cope with this change just like they would any other challenge in Nature. 

Your intentions are good. Your ideas are sound. 

Stay brave. Stay thoughtful. Stay curious. Stay calm. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics



Scott Fellman
Scott Fellman


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