August 25, 2020

The "upside" of detritus..?

Detritus.

The definition of this stuff, 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)

Yeah, doesn't sound great.

Not surprisingly, a lot of hobbyists think that it is so bad.

I'm not buying it.

Why is this necessarily a "bad" thing?

Could there be some "upside" to this stuff?

The Latin root word, is really weird, too: It means "rubbing or wearing away."

Okay...

But really, IS it that bad?

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 also known that detritus may be formed by some types of bacterial aggregations. These may result from the feeding activities of animals, but often they are simply a result of bacterial growth. Detritus can be composed of inorganic mineral grains resulting from the actions of animals burrowing into wood or botanicals, or from ingested larger mineral grains of material, which are only partially dissolved via digestion.

That'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, detritus, 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!

Now, I realize that this stuff- allowing it to accumulate or even be present in your system- goes against virtually everything we've been indoctrinated to believe in about aquarium husbandry. Pretty much every article you see on this stuff is about its "dangers", and how to get it out of your tank. I'll say it again- I think we've been looking at detritus wrong for a long time; perceiving it as an enemy to be feared, as opposed to the "biological catalyst" it really is!

In essence, it's organically rich particulate material.

We've pushed this narrative many times here, and I still think we need to encourage hobbyists to embrace it more.

Yeah, detritus.

Okay, I'll admit that 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 botanical-materials- the end product of biological processing. Yeah, a wide variety of organisms have become adapted to eat or utilize detritus.

There is, of course, a distinction between these two.

One is the result of poor husbandry, and of course, is not something we'd want to accumulate in our aquariums. The other is a more nuanced definition.

As we talk about so much around here- just because something looks a certain way doesn't mean that it alwaysa 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 in a well-maintained system? 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.

Now, I'm just one guy, but I personally haven't 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.

Of course, if you're allowing large quantities of uneaten food and fish poop to accumulate in your aquarium, that's a very different distinction. Such materials accumulating will contribute to nitrate and phosphate accumulation in closed aquatic systems unless removed or acted upon by organisms residing in the aquarium. So, our love of detritus shouldn't be a surrogate for poor husbandry- ever.

I have always been a firm believer in some forms of nutrient export being employed in every single tank I maintain. Typically, it's regular water exchanges. And, not "when I think about it', or "periodically", mind you.

Nope, it's weekly.

So, yeah- I'm not saying that you can essentially disobey all the common sense husbandry practices we've come to know and love in the hobby (like not overcrowding/overfeeding, etc.) and just change the water weekly and everything's good, either.

Water exchanges are helpful.

However, they're not a panacea for all of the potential "ills" of a poorly managed tank. You need to master thewell-known basics of aquarium care. Period. You know this, of course...right?

And you could employ some well-known friends to help you keep detritus well-managed in your aquarium, such as snails, like the Malaysian Livebearing Snail, fish like catfishes and loaches, and all sorts of worms, like blackworms, and even organisms like Gammarus.

Think about the potential benefits of allowing some of this stuff to remain.

Think about the organisms which feed upon it, their impact on the water quality, and on the organisms which fed on them. Then, think about the fishes and how they utilize not only the material itself, but the organisms which consume it.

Consider its role in the overall ecosystem...

So....IS detritus a nutrient trap?

Or is it a place for fishes to forage among? A place for biodiversity to arise.

A place for larval fishes to seek refuge and sustenance in? Kind of like they do in Nature, and have done so for eons?

Yes, I know, we're talking about a closed ecosystem here, which doesn't have all of the millions of minute inputs and exports and nuances that Nature does, but structurally and functionally, we have some of them at the highest levels (ie; water going in and coming out, food sources being added, stuff being exported, etc.).

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. Test your water. Observe the health of your fishes. Draw parallels to the natural aquatic ecosystems of the world. Look at this "evolution" process with wonder, awe, and courage.

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.

Ahh..this "stuff."

This "annoying" end product of decomposition, and the life forms that accompany/produce it can actually be one of the most beautiful, elegant, beneficial friends that we can have in the aquarium...

We just need to embrace them all. 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 ideas on stuff. It's not always pretty.

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.

Open your mind up and reconsider the "upside" to detritus.

Stay thoughtful. Stay engaged. Stay open-minded. Stay curious...

And Stay Wet.

Scott Fellman

Tannin Aquatics