What is detritus exactly?

[biom]

It is a hobby term that is applied to many things and currently means nothing specific. Might be more informative if we start dealing with UFO’s - unidentified floating objects - one at a time. What material are you asking about?

That is simply not correct, detritus is not a hobby term and has biological definition (check Wiki).

 

[brandon429]

Sand Bed

I have a stable, successful (by my standards) tank for many years. I has a dsb which may or may not be relevant to that. Seems like all I read about DSB is anecdotal. So, I will add to it. I had to excavate a small section of my sand bed for a plumbing issue. With in 12 hours, both my tangs...

www.reef2reef.com

This thread is additional context harry

I have 20 more of these examples. The two posted are clear enough for you to understand


When he mentions stuff dying, what composition caused that loss, was it the water? Inside the thread key terms stand out

 

[EeyoreIsMySpiritAnimal]

What?

No idea either!

 

[brandon429]

Any source you search out Harry shows detritus is tank waste. Randy defined it further on page one

You asked if it's inert, you can see sometimes its not.

 

[harrylarry]

Any source you search out Harry shows detritus is tank waste. Randy defined it further on page one

You asked if it's inert, you can see sometimes its not.

Im sorry but I don’t understand what you are trying to say. Ya, we all know it’s tank waste. I was looking for more details on what exactly as people mostly say it’s fish poo, but it’s not just that.

 

[GARRIGA]

Im sorry but I don’t understand what you are trying to say. Ya, we all know it’s tank waste. I was looking for more details on what exactly as people mostly say it’s fish poo, but it’s not just that.

Detritus can mean various things including rock rubble in geology but as I understand it in biology it’s the remnants of organic matter such as uneaten food, poop and different stages of decomposition. Final stage being humus which takes longer to finally decomposed called mineralization where minerals such as calcium are released. This final stage I believe can take decades or centuries to decompose based on my research but can be accelerated using bio digesters for which I can’t find exactly how to deploy in an aquarium environment.

Because detritus can be utilized by various organism is why I don’t fear detritus or obsess with its removal. Rather let it decompose to mulm (humus) and then either remove that or find a way to accelerate mineralization. Latter preferred. Former requires a method of capturing that final stage for disposal.

I believe mulm to be inert as it’s no longer carrying that which can pollute the water and now just contains that which can provide value in the form of minerals. As I understand it. This is same as the top layer found in soil and what farmers pay a fortune to use as a form of fertilizer. Yet we toss it because we either can’t convert it or don’t understand it.

 

[Dan_P]

That is simply not correct, detritus is not a hobby term and has biological definition (check Wiki).

Agreed, it was not invented by the hobby, but as a term used in this hobby, it has been rendered meaningless.

 

[Thales]

I would also add that it's not just ordinary decomposition that roller mats and other particulate removal schemes reduce, but also consumption by filter feeders, which may be a much faster way to convert those same particulates into dissolved nitrate and phosphate.

How quicky do you think food breaks down into inert stuff in our tanks. Like a single uneaten PE mysid Thanks

 

[mrjoe]

Before and after pics from using a turkey baster. Tons of detritus. My N&P get as high as I let it without carbon dosing. No mechanical filtration. No WC. No skimmer. Overfeed two to four times per day. Just nature doing its thing.

No corals. Just fish. Testing decomposition. I’m not worried about detritus beyond the point it’s not aesthetic but better flow can solve that.

yup.. that's exactly what happens when I clean off my rocks.. I get worried that at some point my fish will be killed by that stuff or my zoa's will die off..

 

[GARRIGA]

yup.. that's exactly what happens when I clean off my rocks.. I get worried that at some point my fish will be killed by that stuff or my zoa's will die off..

Tropic Marin now selling a phosphate particulate to mimic corals feeding off detritus on the reefs. End of day. I don’t fear detritus and it settles quickly but wished I’d went into my filter where I suspect will decompose quicker

 

[Dan_P]

How quicky do you think food breaks down into inert stuff in our tanks. Like a single uneaten PE mysid Thanks

@taricha, do you a feel for decomposition rates?

 

[biom]

How quicky do you think food breaks down into inert stuff in our tanks. Like a single uneaten PE mysid Thanks

It depends on so many things and not really possible to be estimated. But cellulose for example is real nightmare for decomposition in salt water. It can take months before is completely metabolized to CO2 in aerobic environment. Algae are producing cellulose real fast and algae eating fish (as Tangs) can digest only very small part of it, the rest of it as excrements becomes main part of the detritus. But excrements of algae eating fish are dangerous for the corals and can cause necrosis, that is why blasting detritus in the reef tank could have adverse effect on corals. I've seen this negative effect on plating montipora during my detritus experiment

 

[Randy Holmes-Farley]

How quicky do you think food breaks down into inert stuff in our tanks. Like a single uneaten PE mysid Thanks

I don't know, except that I expect it is far faster if eaten by something like a worm or sea cucumber, or even other mysids. I suspect bacteria alone may take weeks to break down a mysid.

 

[taricha]

How quicky do you think food breaks down into inert stuff in our tanks. Like a single uneaten PE mysid Thanks

@taricha, do you a feel for decomposition rates?

Let's say 1-1.5 weeks. You could I'm sure speed it up double if you tweak the aeration, stirring, temp etc. or slow it down by tweaking conditions in the other direction.
Here's what I got from looking at decomposing/digesting 100mg/L ground fish flake (so smaller particles than a mysis) in bottles on orbital shaker with aquarium bacteria. It gives an ammonia vs time profile like this (collection of a few different experiments)

The fish flake I used had the nitrogen capacity to generate 10ppm as ammonia.
around day 5: under 50%
7 day digestions were around 2/3 of max.
around day 10: 80%
(Later experiment data not on this chart) day 14: still around 80-85%

This is only the protein remineralization to ammonia part. As @biom said, some organic carbon forms can be way slower.

 

[Thales]

Let's say 1-1.5 weeks. You could I'm sure speed it up double if you tweak the aeration, stirring, temp etc. or slow it down by tweaking conditions in the other direction.
Here's what I got from looking at decomposing/digesting 100mg/L ground fish flake (so smaller particles than a mysis) in bottles on orbital shaker with aquarium bacteria. It gives an ammonia vs time profile like this (collection of a few different experiments)

The fish flake I used had the nitrogen capacity to generate 10ppm as ammonia.
around day 5: under 50%
7 day digestions were around 2/3 of max.
around day 10: 80%
(Later experiment data not on this chart) day 14: still around 80-85%

This is only the protein remineralization to ammonia part. As @biom said, some organic carbon forms can be way slower.

Thanks. I am always trying to get a feel for the utility of filter socks. My reefing thumb tells me that if you aren’t cleaning them daily, you might be making work for yourself. If feel more strongly the longer people wait to clean them, and that if you are aren’t. Cleaning them daily, you are prolly better off letting critters in your tank do their job.

 

[taricha]

Thanks. I am always trying to get a feel for the utility of filter socks. My reefing thumb tells me that if you aren’t cleaning them daily, you might be making work for yourself. If feel more strongly the longer people wait to clean them, and that if you are aren’t. Cleaning them daily, you are prolly better off letting critters in your tank do their job.

Now the question makes more sense. I was thinking about your hypothetical uneaten mysis in a tank and trying to figure out how such a thing could actually exist!
But yes, mysis in a filter sock might put stuff into the water ~10 times longer than the breakdown process it would go through if it was just eaten by the critters in a tank.

 

[GARRIGA]

Now the question makes more sense. I was thinking about your hypothetical uneaten mysis in a tank and trying to figure out how such a thing could actually exist!
But yes, mysis in a filter sock might put stuff into the water ~10 times longer than the breakdown process it would go through if it was just eaten by the critters in a tank.

Perhaps why bristle worms are unsung heroes just like GHA which filter all that gunk because we’ve deemed both unsightly :thinking-face:

Loaded up on Nassarius for this specific reason but they don’t seem to eat poop but do seem to eat uneaten food and dead fish so long as it doesn’t get trapped on top of the rocks. Still trying to acquire the worms. Trying to grow GHA outside the display. Latter too unsightly :face-with-rolling-eyes:

 

[Thales]

Now the question makes more sense. I was thinking about your hypothetical uneaten mysis in a tank and trying to figure out how such a thing could actually exist!
But yes, mysis in a filter sock might put stuff into the water ~10 times longer than the breakdown process it would go through if it was just eaten by the critters in a tank.

Thanks!
I don’t think an uneaten mysid could exist in a ‘functioning’ tank because there is too much that would want to eat it.
I also think that you wouldn’t get a mysid to not break down quickly in a Sox due to violence of the water motion and ester pressure in most filter socks.
I’d like to hear your thoughts on the efficacy of filter socks. Unless they are cleaned every day, I don’t think they are all that useful as a constant filter.

Hope you are enjoying the weekend

 

[taricha]

I’d like to hear your thoughts on the efficacy of filter socks. Unless they are cleaned every day, I don’t think they are all that useful as a constant filter.

I haven't ever used a filter sock, so I don't have a great feel for how systems behave with one in place.

But here's an analogy/illustration on the idea of a filter sock as a food catcher: I usually feed fish food by putting it in a cup and swirling it with a little tank water before I pour it in the tank. Sometimes I forget to feed it all and leave some in the cup.
The next day - that cup is rank. I can smell it from across the room.
So quite a bit of the material that was in the food has been broken down into decomposition products that could pass through a filtersock. Is it done? not close - breakdown processes would continue for many more days - but if that cup of fish food was instead in the filter sock, much of the same things would be happening. That food would be partially broken down into stuff that would pass through the filter (soluble proteins, organics etc.) and go into the tank water.
I'm glossing over significant differences about aerobic and anaerobic decomposition etc.
Maybe the better illustration is this. Let's say you put some mysis in a bottle of tank water, and aerated it overnight. The next day there would be lots of material in that water as a result of breakdown of themiysis in that bottle. Would you feed that day old aerated mysis water to your tank? Some may say yes. I think most would say no, as would I.