The "Unholy Trinity" and the Mental Shifts we must make...

The aquarium hobby tends to latch on to all kinds of ideas, practices, suppositions, and convenient facts. Much of what we believe in- or have been told to embrace, is good, solid stuff with practical applications. Some of it, however, is based on old information, uncorrelated facts, and simple fears.

We have been indoctrinated since our earliest days in the hobby to create optimum conditions for our fishes by scraping algae, removing biofilms, and siphoning out detritus.

Stuff that we, as lovers of botanical-style aquariums have learned not to be so stressed-out about, right?

Removing and eliminating those things from our tanks has become one of the biggest concerns for aquarists; algae control alone has become a lucrative category within the hobby, with tons of products, additives, tools, and gear dedicated to its eradication.

As aquarists, we're constantly made to think about the "perils" which the presence of naturally-occurring biological products can cause for our tanks. The reality is that most of our fears are, in my opinion, not only unwarranted, but are completely over-emphasized.

Often, our attempts at eradicating them leads to the formation of the very imbalances we are so consistently fearful of.

Let's start with one of the cornerstones of this "Unholy Trinity" of aquarium "scourges"- algae!

As we have literally beaten into your head relentlessly, in our truly "natural style" tanks, we don't really care if there is some algae in there. We've made that "mental shift" that says it's okay to have some decomposing botanicals, brown water, biofilms, and yeah...algae. Because natural aquatic habitats do, too. So it's not so bad, right?

Um, well, it isn' least in theory.

Let's think about algae in the aquarium to begin with...No, not the boring old "This is how algae problems happen in our aquariums..." lecture that you've read on every website known to man since the internet sprung to life. You can find that stuff everywhere. There are as many articles about how to control algae as there are aquarists.

Rather, let's think about how we, as a group, mentally are opposed to the stuff in our tanks. I mean, yeah, I know of no one that really enjoys a tank smothered in algae. It looks like crap, and is a "trophy" for incompetence in the eyes of most aquarists. In fact, I remember reading once that more people quite the aquarium hobby over algae problems than almost anything else.


Well, sure- algae problems caused by obvious lapses in care or attention to normal maintenance, like overfeeding, lack of water changes, gross overstocking, etc., are signs of...incompetence. The occasional algae outbreaks that many hobbyists suffer through have all sorts of other potential causes, and can often be traced to a combination of small things that went unchecked, and are typically controlled in a relatively short amount of time once the causative factors are identified.

Yet, as a group, us hobbyists freak out about algae in our tanks. I can show you a hundred pics of algae in the wild and say, "See it happens here too! Natural!" and the typical hobbyist will still be rendered speechless with horror should the stuff show up in their home aquarium.

We simply don't like the visuals of algae in our tanks. I get it. And excessive amounts of almost anything are indicative of an imbalance. However, since we are so into natural-style aquariums, isn't a little algae in our tanks...natural?

Is the presence of algae always a bad thing?


Algae is among the oldest, most adaptable life forms on the planet, and will exploit every available opportunity to flourish. Perhaps the biggest irony about algae is that, despite our disdain for the stuff, it's consuming some of the very nutrients that you don't want accumulating in the first place!  The real scourges! Its presence is quite beneficial in many cases, as it is an efficient processor of organics, produces oxygen, serve as food for many aquatic creatures and provides a "substrate" for small crustaceans and other life forms which our fishes consume as part of their diet.

When you think about it, the appearance of algae in the aquarium is actually an indicator that thing are functioning pretty well!

Sure, the "dark side" to algae is that it can smother your plants and cover everything if left unchecked. Now, that IS the sign of an unbalanced aquarium, when it's growing faster than your plants, or literally taking over every surface. And who willingly lets that happen?  No one. Some growth of algae on rocks and wood is not only not cause for alarm, it's really a natural and almost inevitable thing.

Wild aquatic habitats are filled with the stuff.

Yet, we have been trained over the century or so that we've been keeping aquariums to loathe the appearance of algae; to fear it and take drastic action when we see it. The bulk of the algae "problem", IMHO, is in our minds. It's that it's been perceived as an affront to our aesthetics in the mainstream hobby, because we've been told that an aquarium should appear near "sterile", or at least, devoid of any growth that we think is "unattractive."

And I think that's kind of sad.

The reality is, algae growth is important.

Again- algae is seen everywhere on the planet, and it's all over rocks, wood, and other submerged objects in natural watercourses. It's part of the rich fabric of life. Accepting that some algae is not only acceptable, but actually aesthetically interesting will take a "mental shift"- along the lines of the one that we make when we embrace a botanical/blackwater aquariums and its accompanying tinted water, decomposing botanicals, and biofilms. 

It's actually not only "part of the aesthetic" of underwater habitats, it's part of the necessary ecological framework. And that makes it a beautiful thing, doesn't it?Removing every bit of algae from your tank is not only impossible- it's impractical. And unhealthy for you aquarium.

So, next time you notice a little algae growth here and there in your tank, don't run off in a panic and reach for the algicide. Look at it and ask yourself if it's really "taking over" the tank,smothering your plants- or just exploiting a niche that's available to it.

Ask yourself if it's becoming a burden or danger to the fishes, or simply a "distraction" that you've been accustomed to fearing and reviling throughout your aquarium "career."

Along with algae, perhaps the most misunderstood biological occurrence in our botanical-style aquariums is biofilm.


Fairly regularly, we get emails or DM's asking about the "stringy stuff covering my leaves"- so it's always a good idea to discuss it from time to time.

Even the word conjures up an image of something that you really don't want in your tank. Something dirty, yucky...potentially detrimental to your aquarium's health. 

And, let's be honest with ourselves here. The damn dictionary definition is not gonna win over many "haters":

bi·o·film -ˈbīōˌfilmnoun -a thin, slimy film of bacteria that adheres to a surface.
Some charming and commonly-encountered examples of biofilm include plaque that forms on teeth, and the slime that forms on surfaces in water.
Shit. Really?
Add this to the fact that it's not the best-looking stuff you could find in an aquarium and- well, yeah..Its reputation proceeds it, right?

Yeah, I guess that's the definition we have to run with.

Well, apart from the unpleasant-sounding description of the stuff, and it's "snot-like" appearance, the concept of biofilms and how they form is actually kind of interesting.

Not "charming." I didn't say that. But interesting, for sure.

Biofilms form when bacteria adhere to surfaces in some form of watery environment and begin to excrete a slimy, gluelike substance, consisting of sugars and other substances, that can stick to all kinds of materials, such as- well- in our case, botanicals.

They are an integral part of flooded forest habitats...and pretty much every aquatic habitat there is. They assist with nutrient processing, sediment stabilization- oh, and they provide food for many fishes, too.

Is there a "darkside" to biofilms? Of course there is.

Like anything else, too much of a "good thing" can cause problems in rare instances.

Frightening, "aquarium armageddon scenarios" could play out. For example, in an extremely overcrowded aquarium (or a very small one) with marginal husbandry and filtration, with a huge amount of biofilm (relative to tank volume) caused by an equally huge influx of freshly-added botanicals, there is always the possibility that bacteria within the biofilms can multiply extremely rapidly, reducing the level of oxygen in the rest of the aquarium, which could lead to a dramatic increase of CO2 being released out of the water.

This, in turn, could lead to CO2 levels rising quickly and sharply, potentially causing asphyxiation to the animals in the tank- including the lovable nitrifying bacteria that support it.

Now, that's a true "doomsday scenario"- brought about by a non-sustainably-managed/populated aquarium, improper preparation and rapid, excessive additions of botanicals, and complete lack of common sense on the part of the aquarist, in terms of husbandry.

So yeah.

There IS a darkside to biofilms. If you create circumstances to foster one.

The real positive takeaway here: Biofilms are really a sign that things are working right in your aquarium! A visual indicator that natural processes are at work.

Yet, understandably, it may not make some of you feel good. However, it being "natural" and all...perhaps you could take some comfort in hearing more about what to expect?

First off, take comfort in the fact that this is typically sort of a "passing phase", and can take anywhere from a few days to 2-3 weeks before it subsides on it's own to some level that you can live with.  It will never fully "go away." You don't WANT it too. Realize that biofilms are present in every aquairium, to some degree. Yeah, even your "Nature Aquariums", guys.

Welcome to Planet Earth.

We get it, though- some of you just don't want this stuff, despite its "charms."

You can't remove every speck of it. You wouldn't want to. Like algae, biofilms serve as a primary means of nutrient export in our aquariums, and to remove them from the ecosystem would simply be detrimental. 

Again, the reality here is that in an otherwise well-managed, sustainably-populated aquarium, at best the largest blooms of the stuff will be a temporary nuisance, subsiding to a tolerable level, or even being almost unseen, for as long as you have the aquarium in operation.

Remember, it's all part of the game with a botanical-influenced aquarium. A part of that "mental shift" towards accepting and appreciating a more truly natural-looking, natural-functioning aquarium. The "price of admission", if you will- along with the tinted water, decomposing leaves, etc.

Biofilm blooms and their ultimate stable long-term presence in your tank are simply part of the "dues you pay", which ultimately go hand-in-hand with the envious "ohhs and ahhs" of other hobbyists who admire your completed aquarium when they see it for the first time.

Now, there are a lot of hobbyists who have come to admire, and even love the whole idea of biofilm. Like, those of you who love the ornamental shrimp. You understand the value of having a periodic "crop" of this stuff available for your shrimp to "graze" upon.

You actually are wanting to foster it. 

Biofilms are absurdly common in Nature, and a part of pretty much any aquarium, yet a bit more significant (and noticeable) when you play with aquatic botanicals. They are not to be feared- although they should be respected, studied, understood- and ultimately, utilized as food by aquatic animals!

Moving on to the last member of our little triad...Equally maligned and misunderstood. 

As those of you who read my little rants and listen to my podcasts know, one thing I truly can't stand is over-generalizations about stuff in the hobby.

And one of the most maligned, over-generalized topics in the world of aquarium husbandry is...detritus. We've talked about this before, but it deserves repeating...

My never-ending war on behalf of detritus continues.

Yeah, you heard me...On BEHALF of detritus!


Look, I know that  detritus comprised of uneaten food and fish poop, accumulating in a closed system can be problematic-especially  if overall husbandry issues are not attended to. I know that it can decompose, overwhelm the biological filtration capacity of the tank if left unchecked. And that can lead to a smelly, dirty-looking system with diminished water quality. I know that. You know that. In fact, pretty much everyone in the hobby knows that.

Yet, we've really sort of heaped detritus into this "catch-all" descriptor which has an overall "bad" connotation to it. Like, anything which is allowed to break down in the tank and accumulate is bad. Anything that looks like "dirt" is...well, "dirty", dangerous, and should be treated accordingly.

Now, "dirty-looking" and "dangerous" are two very different things, right?


The definition as accepted in the aquarium hobby is kind of sketchy in this regard; not flattering at the very least:

"detritus is dead particulate organic matter. It typically includes the bodies or fragments of dead organisms, as well as fecal material. Detritus is typically colonized by communities of microorganisms which act to decompose or remineralize the material." (Source: The Aquarium Wiki)

Everyone thinks that it is so bad.

I'm not buying it.

Why is this necessarily a "bad" thing?

I mean, even in the above the definition, there is the part about being "colonized by communities of microorganisms which act to decompose or remineralize..."

It's being processed. Utilized. What do these microorganisms do? They eat it...They render it inert. And in the process, they contribute to the biological diversity and arguably even the stability of the system. Some of them are utilized as food by other creatures. Important in a closed system, I should think.

This is really important. It's part of the biological "operating system" of our aquariums. It's largely inert.

It's not all bad, right?

I think we should embrace this. Especially in a botanical-style aquarium, which essentially "runs" on the decomposition of materials.

In the flooded forest floors we find in Nature, the leaf litter "community" of fishes, insects, fungi, and microorganisms is really important to the overall tropical environment, as it assimilates terrestrial material into the blackwater aquatic system, and acts to reduce the loss of nutrients to the forest which would inevitably occur if all the material which fell into the streams was washed downstream!

Stuff is being used by a myriad of life forms.

Is there a lesson from Nature here that we can incorporate into our aquarium work?

I think so!

Okay, detritus as we see it may not be the most attractive thing to look at in our tanks. I'll give you that. It literally looks like a pile of shit! However, what we're talking about allowing to accumulate isn't fish poop and uneaten food. It's broken-down (processed) botanical-materials. 

As we talk about so much around here- just because something looks a certain way doesn't mean that it always a bad thing, right?

What does it mean?

Take into consideration why we add botanicals to our tanks in the first place. Now, you don't have to have huge piles of the stuff littering your sandy substrate. However, you could have some accumulating here and there among the botanicals and leaves, where it may not offend your aesthetic senses, and still contribute to the overall aquatic ecosystem you've created.

If you're one of those hobbyists who allows your leaves and other botanicals to break down completely into the tank, what happens? Do you see a decline in water quality? A noticeable uptick in nitrate or other signs? Does anyone ever do water tests to confirm the "detritus is dangerous" theory, or do we simply rely on what "they"say in the books and hobby forums?

Is there ever a situation, a place, or a circumstance where leaving the detritus "in play" is actually a benefit, as opposed to a problem?

I think so. 

Test your water. Observe the overall health of your fishes and the aquarium...How problematic IS the presence of some detritus in your tank?  It likely isn't, just like it isn't an issue in Nature.

Now, I'm just one guy, but I personally haven't ever had issues with the complete decomposition of botanicals and leaves being left to accumulate in my aquariums. In almost three decades of playing with this stuff, and being a hardcore, water-quality-testing reef keeper during much of that time, I can't ever, EVER recall I time where the decline of a system I maintained could be pinned specifically on the detritus from decomposing botanical materials as a causative factor in reducing water quality.

In fact, I have never had a situation where water quality has been an issue in a tank not performing well. And I suspect- neither have many of you.

Incorporating regular water exchanges into your botanical-style aquarium system is vital.  It gives you the ability to dilute any potential accumulating organics/pollutants before they become a significant negative impact on water quality.

They simply give you a bit of a "buffer", essentially.

I don't need to go into the well-trodden reasons about why water exchanges are a good thing in the aquarium. However, I do need to give us a collective whack upside the head and encourage each and every one of us to think about this stuff from the perspective of an overall closed ecosystem. Think about what the nitrogen cycle is and does, and think about the impact of inputs and exports into and out of our closed systems. 


Embracing the presence of stuff like algae, biofilms, and detritus in your tank is not a zero-sum game. It's not like, you either have a ton of it in your tank, or none. Like so many things in the hobby, our aquariums will reach an equilibrium if we let them. The ecology in your aquarium will "find its way", and arrive at an optimum balance between input and export.

If we let it.

Embracing these things is not an excuse for blowing off the basic tenants of aquarium keeping. You still need to take care of your aquairum, even though you might be an "algae hugger."

Now, I get it. Not all of these processes have appealing visuals. I believe that we as hobbyists need to separate aesthetics from the overall functional benefits of the various life forms and processes which appear in and guide our aquairums' ecological systems.

There is so much more to this stuff than to simply buy in unflinchingly to overly-generalized statements like, "detritus is bad."

Stay the course. Don't be afraid. Open your mind.

Study what is happening. Draw parallels to the natural aquatic ecosystems of the world. Look at this "evolution" process with wonder, awe, and courage. And know that the pile of decomposing goo that you're looking at now is just a metaphorical "stepping stone" on the journey to an aquarium which embrace Nature in every conceivable way.

Maybe, as the years go by, we as a hobby will overcome generations of fear over stuff like detritus and fungi and biofilms- the very life-forms which power the aquatic ecosystems we strive to duplicate in our aquariums. Maybe, rather than attempting to "erase" these things, which go against our "Instagram-influenced aesthetics" of how we think that Nature SHOULD look, we might want to meet Nature where she is and work with her. 

And we just might see the real beauty- and benefits- of unedited Nature.

And of course, the literal "basis"- the "fuel- for all of this stuff is the botanical materials themselves, breaking down in our tanks, as they've done in Nature for eons. The ultimate in "ephemeral", and perhaps the ultimate execution of the natural, botanical-style aquarium. 

Ahh..this "stuff."

These small, seemingly "annoying" end products of biological processes like decomposition, and the life forms that accompany/produce them are actually the most beautiful, elegant, beneficial friends that we can have in the aquarium...

We just need to embrace them. Understand what role they play in Nature- and in our tanks.

It's a mental shift.

A perspective of open-minded curiosity...and a willingness to look at things a bit differently and go beyond the usual and generally accepted hobby ideas on "stuff." It's not always pretty. It's not always right.

I'll give you that much. However, it's always, always worth considering and exploring. Because just accepting "status quo", keeping a closed mind to alternative ideas, and not pushing the edges from time to time is not just a little bit boring- it's denying fellow hobbyists the opportunity to learn about- and potentially benefit from- stuff we might have long been afraid of.

Keep exploring. Always. Keep an open mind. Think through what we have taken to be "the gospel" in the aquarium hobby for so long and ask yourself if it could use an addendum or two! 

Stay curious. Stay bold. Stay diligent. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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