Detritus is it as bad as some make out?

[brandon429]

detritus is the cause of OTS in aquariums, and without your offsets, your tank would go eutrophic and not be 40. old tank syndrome has some pretty good published works on the web under the subject. we beat it too, solely with detritus control.

you have calculated safe amnts of 40 yr old detritus, not 40 yrs worth.



no doubt, detritus is marine snow, but we now have retail replacement feeds to take the place of that.

This thread here shows the risk of detritus
https://www.reef2reef.com/threads/t...ead-aka-one-against-many.230281/#post-2681445


detritus is a giant liability unless its planned for, and offset, carefully, then its feed reserves.

that duality is how it should be explained imo. its good in some systems, unless you stick your hand in there and slosh things around and then let the cloud flow, then its horrible.


to know the true effects of stored detritus, try to make an old nano reef keep its detritus and stay alive. remove the dilution/speed up the end results




detritus in place isn't all bad, but people rarely stay in one place Paul for as long, and the clean tanks will always beat the dirty ones where any type of action on the system is required.

during a power outage, a detritus stored tank is under MUCH more risk than an organically clean one, BOD readings would be much worse than a bare bottom system with low organic stores. all the extra aerobic bac farmed on detritus substrate are fine as long as the machine stays running...I know you already weathered an outage as well, but these are facts regarding high organic systems and the double sided coin involved. if the generator that runs a tank during a power outage runs out, that's when BOD matters so greatly, fair angle to consider for those who live in prone areas, don't farm detritus as a safety hedge.
if you are going to be relocating anytime within the life of your tank, then low detritus can be a big safety hedge.

I cannot locate the benefit detritus actually gives to a system, we have feed systems to replace it so that nutrients arent located packed into a sandbed.

if worms and pods are the goal, then a simple remote sandbed would provide that, and be pre filtered of the massive fish waste a display sees. in my nano reefs I don't care about worms and pods as much as I care about coralline covered rock and coral export, detritus lends no benefit to those two goals so I keep it out just my way.

 

[Paul B]

I think I will keep doing what I am doing.

 

[rkpetersen]

I have a heavy bioload, lots of fish and corals and feed heavily 4 times a day plus a heck of a lot of flow. I still get detritus in my sand and sump but IMO it's not a problem. My tanks been set up 22 months and although I blast the sand now and again I don't clean the sump of detritus.

I used to operate just like this. Every so often, take a sea squirt feeder and blast all the sand, including the various nooks and crannies behind rocks. Detritus would form a storm in the water but clear within an hour, and the livestock was always fine with it. Then, one day I did this, and within an hour, I could tell that something was wrong. Acros with polyps that were always massively extended during the day, suddenly weren't. Polyps in general were retracted for all corals. Fish and inverts seemed unaffected. Acute effect lasted about a day, but several corals died within a week. Not at all sure what it was (didn't smell any H2S and none of my monitored water parameters changed), but stirring up the sand was definitely the proximate cause. Some toxin, decomposing animal, or acute drop in dissolved oxygen? So now I minimize my manual sand stirring. I've increased flow further still, and added a sizable fleet of detrivores, primarily nassarius snails both large and small. Have several pistol shrimp who dig constantly, and may get more. Long term detritus accumulation in the deeper sand (max 2") behind rocks does still concern me somewhat. However, while detritus buildup may increase the total biological oxygen demand of the entire system, I'm not convinced that buildup of mineralized detritus in the sandbed increases the BOD of circulating water, where the creatures I care most about live.

I do clean my sump out occasionally now. Instead of doing a water change from the tank, I just do a smaller one from the sump, vacuuming up the debris as I go. This is in the non-refugium sections.

 

[Nano sapiens]

One of the best snippets from the 'The Reef Aquarium' (vol 3):

"The conditioning of a healthy aquarium requires a certain amount of detritus accumulation that promotes a healthy diversity of life within the substrata. Later on, this accumulation can become excessive..."

It's a matter of degree and that degree depends on many factors particular to the system such as size, composition, bioload, etc. What is clear is that a large amount of detritus accumulation in small pico/nano systems typically causes severe issues in just a few short years. Larger systems *can* go on happily for a much longer period of time with large stores of detritus, but many have seen that eventually problems arise.

We discuss a lot about the decomposition of detritus (and rightly so), but much less about the physical effects of a detritus clogged substrate. I think it's safe to say that with such a substrate the reduction in oxygen (and other substances) that would normally enter the substrate via advective processes (and drive essential bacterial processes) certainly contributes to a tank's eventual decline.

Ralph.

 

[rosshamsandwich]

So too much of a good thing can be bad?

 

[Scott Campbell]

I have to agree with Paul and Randy that detritus is beneficial for most tanks. I've never siphoned the first speck of detritus out of my tank in 30 years with no ill effect. I don't even take the steps Paul takes to clean the substrate.

I believe nano-sized tanks struggle with detritus issues simply because the system is not large enough to maintain stable colonies of worms, bacteria, amphipods and such. To argue that detritus must be bad because all nano-sized tanks with detritus eventually crash is a flawed argument. Nano-sized tanks with excess detritus may crash simply because they are nano-sized.

I will agree a system with a heavy microfauna bioload must be aware of oxygen and pH issues. I run multiple air pumps and have multiple power outage back-up plans in place. I recognize my tank will more quickly have problems if the power goes out compared to a tank with less detritus and a less robust population of small critters. But the flip side of that is that I can all but drop a dead squirrel in my tank and the microfauna will be able to deal with it. The system is much more stable and much less dependent on me for that stability.

Bottom line - I love all my worms and my worms love all my detritus. Happy worms = happy tank.

 

[brandon429]

post up such a nano that is older than the current ones who always do detritus mitigation

There's actually one I'm aware of, curious if someone posts it. A twenty year one, show me the build thread tho for details, the web was here 20 yrs ago there should be a trail.

I know it seems ideal to house in perfect ratios the busy, crowded cloudable nature of the large tank sandbed in a nano...those w old nanos currently running tried that way first and got out a few years then changed for a reason

Dilution is letting you guys get away with hands off. That, and never having a sustained oxygen challenge, rock stack shifts, or moves. The entire hobby was built on detritus storage and now a huge offshoot of counter dosers and machinery exist to deal with it.

To curb detritus storage: ats, vsv, rugf, denitrator filters, no pox, etc

I truly believe there are large, old hands off tanks where detritus doesn't harm and that a nano could be guided in such a way to work with mass waste, but we can't get consistency with that. When people run clean nanos, well fed and exported, they always work and have the least invasion challenges.

For sure I don't think one was is bad or good, they're just different. I can say with certainty that the trending of this hobby towards much smaller reefs has been done fully under the rule of detritus control. Were it not for that detail, our minimal accepted reefs would still be forty gallons or they would be three gallon systems so racked with cyano nobody would want them.

The trend to bare bottom reefing...was that because people hated sand grains, or cleaning them?


In my opinion we shouldn't rate the impact of detritus by what the top reefers can do regardless, it's better to check reef trending to see how masses are impacted.

Hands off deep sand beds were shown to be nutrient pumps for the masses, now it's about rip cleans and preventative stirring, solely with the aim of removing detritus.


Where's the twenty seven strirrers who were posting in the how I keep my sandbed clean thread y'all speak up. You didn't start reefing by stirring, you started by storing. What changed you? No3 I bet.

 

[ca1ore]

Count me among those that think detritus to be mostly inert and of only aesthetic concern. Ive performed a few crude tests to support my view. Long been skeptical of OTS.

 

[brandon429]

I'm skeptical of ots models that claim the bacteria didn't self regulate and got out of proportion etc, seen that claim before. My offer is keep out the sludge, the system self regulates forever.

@Lasse he worked in large scale aquaculture:

Lasse-

What happens to nitrification production filtration systems if they aren't backflushed like clockwork?

How is simple ammonia conversion nitrification affected by detritus and sludge accumulation in aquaculture, where bioloads are high and production is high and accumulation is high? I read that detritus blocks nitrification efficiency.

Two extremes outline the impact of detritus. The very large and the very small examples are still working around the impacts of detritus.

I don't think detritus is mega evil -promise- I myself stored it for nine years in a nano test bed logged online. Nine years, it can work. I only changed due to the stronger benefits of the other side, my reef is better set to age further without the extra loading just my opinion.

 

[Scott Campbell]

How much testing was done without the massive crutch of dilution truly I'm interested


I'm skeptical of ots models that claim the bacteria didn't self regulate and got out of proportion etc, seen that claim before.

**heres a tough one to overcome. @Lasse he worked in large scale aquaculture:

Lasse-

What happens to your nitrification production filtration systems if you don't backflush them like clockwork? What is backflushing removing?

How is simple ammonia conversion nitrification affected by detritus and sludge accumulation in aquaculture, where bioloads are high and production is high and accumulation is high?

Two extremes outline the impact of detritus. The very large and the very small examples are still working around the impacts of detritus.

I don't think detritus is mega evil -promise- I myself stored it for nine years in a nano test bed logged online. Nine years, it can work. I only changed due to the stronger benefits of the other side, my reef is better set to age further without the extra loading.

Here's an even more extreme example - "earth". Nobody has to back-flush the planet of detritus. That's because there are worms, bugs and bacteria.

The health of my tank has nothing to do with "dilution". My tank has remained healthy because I'm rather obsessed with maintaining a large and diverse group of worms, shrimps, micro-stars, amphipods, macroalgae and sponges.

Nano-sized tanks are most likely too small to maintain sufficient and stable microfauna populations over an extended period of time. Industrial aquaculture filters are likewise probably ill-suited to support large enough colonies of microfauna to process the sheer volume of waste. I'm not sure these examples are as convincing as you think they are.

If you leave an apple core on the kitchen counter, then yes, it will rot. Place the same apple core in a compost heap and it will be consumed. You seem to be arguing that apple cores are "bad" because they rot on kitchen counters. I don't find that line of reasoning very compelling.

 

[brandon429]

It's cool if you keep detritus I'm aware most large tanks with sandbeds have to, and it's not immediately destructive. I merely named two versions of industry that must deal with detritus.

Why in your opinion did the trend even for large tanks with storage room shift to rinsing and stirring, of detritus? The hands off sandbed has declined markedly. what caused that shift in your opinion and what should have been done instead if we were to keep the 90s dsb method going.

I myself must use a deep sand bed to keep my rock structure up high enough in the tank and for the classic look, by keeping it free of waste (cloudless, can be disturbed and moved at any time) I get the chemistry benefits of the no sandbed tank.

Also the worms you mention... I read that too about marine substrates

How many old aquarium sandbeds are collections of diverse worms and moving animals vs piles of mud?

Our sand rinse thread linked is so far the only thing posted using other people's tanks as an example. That at least establishes some trending all in one place for pattern analysis.

We saw no such critical worms or fauna in a large tank dsb. It's not like I'm trying to judge someone else's approach. Am only saying that our control threads have lots of active examples to show that detritus isn't neutral when accumulated. I'd accept and read anyone else's other people example threads, add to the mix.

We beat cyano and invasive dino infestations by mitigating detritus... by removing the detritus, the associates go as well, these are just themes that emerged in my dealings with detritus and mulm and backflushing where aquaculture also has BoD and pore blockage concerns... surface area reduction etc....all fair and non judgement points as to whether or not detritus accumulation factors into reef eutrophication or not.

If we agree that small tanks must be directly cleaned since they lack animal diversity, that in turn agrees detritus has a negative impact and requires mitigation.

 

[Scott Campbell]

It's cool if you keep detritus I'm aware most large tanks with sandbeds have to, and it's not immediately destructive. I merely named two versions of industry that must deal with detritus.

Why in your opinion did the trend even for large tanks with storage room shift to rinsing and stirring, of detritus? The hands off sandbed has declined markedly. what caused that shift in your opinion and what should have been done instead if we were to keep the 90s dsb method going.

I myself must use a deep sand bed to keep my rock structure up high enough in the tank and for the classic look, by keeping it free of waste (cloudless, can be disturbed and moved at any time) I get the chemistry benefits of the no sandbed tank.

Also the worms you mention... I read that too about marine substrates

How many old aquarium sandbeds are collections of diverse worms and moving animals vs piles of mud?

Our sand rinse thread linked is so far the only thing posted using other people's tanks as an example. We saw no such critical worms or fauna in a large tank dsb. It's not like I'm trying to judge someone else's approach. Am only saying that our control threads have lots of active examples to show that detritus isn't neutral when accumulated. I'd accept and read anyone else's other people example threads, add to the mix.

I can't speak to the trends.

For my own tank - as long as I maintain a robust and diverse population of worms, amphipods, macroalgae and such relative to the waste being generated; then all the waste eventually gets consumed by something. The challenge is to actually maintain that diversity and balance over time. You have to work at it. Closed systems have a tendency to move toward one species becoming dominant - which reduces the overall effectiveness of the "compost heap" approach. But composting waste in an aquarium will certainly work. I understand however why it would not be everyone's cup of tea.

So again - I don't think detritus is the problem. It is certainly not "destructive" (immediately or otherwise). Lack of sufficient critters to deal with detritus would however be a problem. And would certainly necessitate a more hands-on and involved approach by the tank owner.

 

[brandon429]

I haven't found that similar balance for marine setups yet, but it sure is amazing how opposite freshwater work is. My planted tank has fourteen years of unexported detritus...by design I'll never remove it, deep substrate + growing over time/ how crazy in comparison and contrasting.

The impacts of stored mass I find to be polar opposite when comparing long term fw vs saltwater setups at least for smaller models which age at a quick rate. I can find and replicate that exact balance you mention in planted tanks but my search continues for marine ones

 

[rosshamsandwich]

Count me among those that think detritus to be mostly inert and of only aesthetic concern. Ive performed a few crude tests to support my view. Long been skeptical of OTS.

Taste test?

 

[Nano sapiens]

So too much of a good thing can be bad?

Yes. Anything in excess can cause issues.

Water is good for you, but drink too much and you can have hyponatremia. Sugars in small doses is okay, but an excess can causes serious damage to organs such as your heart, eyes, and nervous system. Etc, etc...

 

[Nano sapiens]

I can't speak to the trends.

For my own tank - as long as I maintain a robust and diverse population of worms, amphipods, macroalgae and such relative to the waste being generated; then all the waste eventually gets consumed by something. The challenge is to actually maintain that diversity and balance over time. You have to work at it. Closed systems have a tendency to move toward one species becoming dominant - which reduces the overall effectiveness of the "compost heap" approach. But composting waste in an aquarium will certainly work. I understand however why it would not be everyone's cup of tea.

So again - I don't think detritus is the problem. It is certainly not "destructive" (immediately or otherwise). Lack of sufficient critters to deal with detritus would however be a problem. And would certainly necessitate a more hands-on and involved approach by the tank owner.

The waste in a large system full of micro and macro fauna will be broken down again and again, and eventually one is left with mineralized deposits and a nearly inert material (aka 'mulm'). Since a high rate of substrate turnover over time can occur in such a system, the substrate can remain friable/porous allowing proper advection into the substrate to maintain bacteria productivity/efficiency. This was the core foundation of the DSB idea as promoted by Shimek and as you've shown by example it can work in a large system when the aquarist has an understanding of how to maintain such infauna and is willing to maintain/promote proper conditions therein.

From what I've seen over three decades in the hobby, most aquarists are unable to sustain such a system long term due to a tendency towards smaller system size and 'must have' organisms that can quickly clear out most beneficial detritivores. This, along with the oxygen depletion concerns if the power goes out, are likely the main reasons why the DSB is no longer as common in the hobby as it once was.

The take-away out of all this for me is that the physical disturbance of the substrate is a most important aspect of reef aquarium maintenance if one wants a system to last long-term. Whether it occurs slowly, but steadily, via infauna action or is accomplished quickly by stirring/vacuuming by the aquarist, keeping the substrate (sand, rock, etc.) relatively unclogged is essential IMO.

Ralph.

 

[LEOreefer]

The waste in a large system full of micro and macro fauna will be broken down again and again, and eventually one is left with mineralized deposits and a nearly inert material (aka 'mulm'). Since a high rate of substrate turnover over time can occur in such a system, the substrate can remain friable/porous allowing proper advection into the substrate to maintain bacteria productivity/efficiency. This was the core foundation of the DSB idea as promoted by Shimek and as you've shown by example it can work in a large system when the aquarist has an understanding of how to maintain such infauna and is willing to maintain/promote proper conditions therein.

From what I've seen over three decades in the hobby, most aquarists are unable to sustain such a system long term due to a tendency towards smaller system size and 'must have' organisms that can quickly clear out most beneficial detritivores. This, along with the oxygen depletion concerns if the power goes out, are likely the main reasons why the DSB is no longer as common in the hobby as it once was.

The take-away out of all this for me is that the physical disturbance of the substrate is a most important aspect of reef aquarium maintenance if one wants a system to last long-term. Whether it occurs slowly, but steadily, via infauna action or is accomplished quickly by stirring/vacuuming by the aquarist, keeping the substrate (sand, rock, etc.) relatively unclogged is essential IMO.

Ralph.

Thats a great write up, I have a 50 cube and minimal sump space. I do have detritus in my sump but I also run a mesh filter sock on my system most days. I started my system with all dry rock ....... so here's the golden question, How does one with a smaller system build a healthy micro fauna and pod population? I have zero room for a fuge and I have a wrasse, scooter blenny, and a coral beauty angel that are all seen at picking at the rock work all day long. I consider my self to have a healthy system as its 7 months old now but I strive to have a healthy pod population as well as micro fauna both for my fish and corals .

 

[Sallstrom]

The way I run "my" reef tanks at work my goal is to never have to clean the sand. Some of them have been running for over 10 years now. Some of them are very low nutrients system.
I like to just monitor the water parameters and clean the windows. And sometimes the skimmers

So IMO detritus is not bad. The tank/ecosystem should be able to handle it, if it's properly designed.

And water changes are overrated too..

/ David

 

[Paul B]

How many old aquarium sandbeds are collections of diverse worms and moving animals vs piles of mud?

Mine is. I have tube worms all the way down to under my UG filter. People have problems with detritus because they don't run a reverse UG filter.
I just stir it so it doesn't clog but I see no detritus in my tank anywhere, not even a little but I use gravel, no sand and I can keep multiple pod eaters for years with no problems. Pods need detritus to find food and pod eaters need pods. It's an ongoing ecosystem.
I am going to move my tank shortly and I am sure when I remove that gravel, the water will look like ink.
To me detritus is a good, natural thing and it is needed. New tanks with no detritus are not healthy as there is nothing to start the food chain.
Fish don't just need the food we give them unless you are just keeping predators. My gravel is full of amphipods, pods, worms and all sorts of things. My fish are spawning and when they do that they stir up the gravel with their tails causing a cloud of detritus. This is food for the thousands of tube worms and spaghetti worms. My fireclowns do that constantly clowding much of the tank. I love it because it's a complete, natural ecosystem.
These guys spawn every few days and stir up the gravel making holes all the way down to the UG filter. The rest of the fish and corals love it and it's what happens in the sea.

 

[brandon429]

My question was how many though

If your tank was lacking biodiversity after twenty seven trips to a local tidal mud flat teeming with a billion amphipods I might accuse you of keeping too many mandarins heh

The majority of us are landlocked, ipsf closing, we’re diversity doomed pretty much