Tested detritus-filled water

[reefwars]

i mean who here has ever added 40 micro stars or worms etc. and can tell me the actual number they have 5 yrs later?


it cant be done ,not realistically anyways ..... these animals cant be kept track of so is hard to say exactly what they are doing at any given , or the overall effect and im sure many other variables

interesting topic though...and i think RC needs a biology forum ( maybe we do and im just off lol )

proven that they help clean a tank and general house maintenance .....yes

proven that they can stop a potential crash from happening or are a deciding factor in a healthy reef is going to be hard to prove

 

[boxfishpooalot]

What effect does biodiversity have in this respect?

A tank crash due to detritus, variety is good, no? But a tank crash as far as adding chemicals, no amount of biodiversity will solve that. I mean we can't add biodiversity to combat low alkalinity or calcium. But you and others know that pods will eat detritus, worms, and bacteria too. Look at zeovit, that's based on biodiversity of bacteria.
But maybe biodiversity is the wrong word.

 

[bertoni]

I don't see why diversity would change the tendency of a tank to crash due to detritus. That seems counterintuitive to me. For example, ammonia can cause a tank crash, and the amount of ammonia produced per unit time is a function of the rate of protein metabolism. How does diversity affect that?

 

[Paul B]

so I'm questioning the common belief that detritus, if left unchecked and if my testing methodology was an accurate way to determine what is being released, should be such a concern.

I also question it and IMO it is a farce. I feel detritus is the end product of decomposition and siphoning it or leaving it there is no different. There is no visible detritus in my tank because I run a reverse UG filter. (OK stop laughing unless your tank is older then mine, and it is not) :lol:
Once a year I stir my gravel and suck out some detritus but I am sure there is some in there from when Nixon was President. The corals don't seem to care nor do the 23 year old fish. I also feel that if you have enough and the correct bacteria, you need not worry about detritus, nitrates or phosphorous. I don't. :dance:

 

[Bilk]

It is both. Hydrolysis of proteins and other biomolecules happens at any pH, but is accelerated by enzymes or by high or low pH. Oxidation with O2 and other reactive molecules also takes place.

All heterotrophic organisms that consume organics release msot of the N and P in those organics because they have a higher need for the energy from the organic degradation than they have for N and P to build new tissues.

You, for example, release nearly all of the N and P in the foods you eat, and it is true of every heterotrophic organism.

The reason all tanks need to deal with N and P is because fish and other organisms that eat food excrete it directly. Nearly all the N and P they eat ends up int eh water as phosphate and ammonia.

Bilk -

Regarding your original question, your results make quite a lot of sense with respect to the physical chemistry aspects of solubilization and the partitioning of nutrients between organic and inorganic forms.

Most test kits are only designed to react with inorganic forms of nutrients (i.e., free PO4- and NO3- dissolved in the water), and won't quantitate more complex organic molecules that contain nitrogen and phosphorus. So environmental chemists will perform a more complex procedure called "digestion" that converts all of the chemical species in a sample to their simplest, oxidized forms. One then quantitates the total phosphate/nitrate in the digested sample, and subtracts the results from the un-digested sample. That yields a good estimate for the partitioning between the organic and inorganic forms of the nutrients.

The digestion procedure varies, but one example is acidifying the sample with nitric acid, then boiling it for 30 minutes. This isn't something I'd recommend to a hobbyist without a chemistry or other science background. Not only is nitric acid one of the compounds on the DOT watch list (it can be used for nefarious purposes), boiling mineral acid is quite dangerous without the proper equipment and knowledge.

A better plan might be to do some research to come up with a few papers where the authors have quantitated phosphorus and nitrogen in marine sediments. While I don't have any of those references at hand, I'm certain they're out there - ocean nutrient partitioning is of great interest in the scientific community.

I also question it and IMO it is a farce. I feel detritus is the end product of decomposition and siphoning it or leaving it there is no different. There is no visible detritus in my tank because I run a reverse UG filter. (OK stop laughing unless your tank is older then mine, and it is not) :lol:
Once a year I stir my gravel and suck out some detritus but I am sure there is some in there from when Nixon was President. The corals don't seem to care nor do the 23 year old fish. I also feel that if you have enough and the correct bacteria, you need not worry about detritus, nitrates or phosphorous. I don't. :dance:

Thanks everyone for the responses. Detritus isn't a new subject for me or pretty much anyone who has kept reef tanks of one form or another. A better understanding of the subject is what I was looking to initiate. Seems there's plenty of opinions on what to either do about it or not do about it. There also seem to be differing opinions on the impact it has on our systems. Randy did provide me with a better explanation of the physical/chemical mechanism which further breaks down detritus to release nutrients into the water column.

I'm sure it's been posted here somewhere before, but will post it into this thread for posterity

The Infamous Detritivore

Oh Paul, I came across a thread you started on Reef Sanctuary on this very subject while searching around for articles and such. Going to be reading that thread later today


.................

 

[Paul B]

Oh Paul, I came across a thread you started on Reef Sanctuary on this very subject while searching around for articles and such. Going to be reading that thread later today

I will have to look for it as I write somewhere between Hemmingway and Dr. Seuss.

 

[Boom]

Ah ok So would a better testing method be to leave the collected detritus in the water for a longer period before measuring? Is maintaining the same relative temperature of the tank important to this? If it's a time vs release mechanism, I assume readings at different intervals would prove necessary to somewhat determine the rate of release?

I'm really no chemist/biologist if you couldn't tell :fun4: So I had to look up abiotic degradation I only found references to it relating to chemicals, plastics and the like. Wiki had an article that has since been removed. Here's the initial definition:



So what precipitates the breakdown or release of the bound PO4/NO3? I'd assume bacteria act upon detrital matter, but then the PO4/No3 are being consumed. I can also see how acidification would cause it to be released, but our systems are alkaline. Does acidification happen in a localized region where detritus accumulates?

I guess what I'm trying to convey is, we believe that detrital matter has bound N&P, but what is the mechanism that releases it?

I asked Randy the same question but in a different light on a different forum recently. I performed the same experiment you did but for a different purpose.
I also tested my water in the tank and the water I removed with detritus for phosphates... with the same results. I then mixed Mrs Wages lime (one baby teaspoon in 5g dirty tank water. The dry kalk functioned as a flocculent. I allowed it all to settle on the bottom and retested the clear water for phosphates. I got a zero phosphate reading... twice.The clear water I drew off, I recycled and used in different cultures. The precipitated stuff I added to a phytoplankton culture with great results.
I asked the question: How could I re-release the precipitated nutrients to make them more available to my phytoplankton or would those nutrients automatically be re-released into a water column that already had lower nutrient concentrations, different temperatures, and ph. As you posed, our saline, alkaline water columns (I presumed) might create a different chemical environment.
Apparently not. According to RF-H, the thermodynamics of organic AND inorganic solutes remain IN FLUX. Randy, I hope I am not butchering this interpretation of what you explained to me earlier .

Since the chemical composition of our reef tanks is different, I vote we all do an informal experiment and report back the results!
I wish there was a cheap way to test the elements (trace if any) locked up in our detritus or the milky precipitate found in our sand beds

 

[bertoni]

The precipitated nutrients will redissolve when the water column is below the equilibrium point. I'd expect a lot of the phosphate to redissolve if added to zero-phosphate saltwater, and more will redissolve as the phytoplankton consume the nutrients.

 

[Boom]

The precipitated nutrients will redissolve when the water column is below the equilibrium point. I'd expect a lot of the phosphate to redissolve if added to zero-phosphate saltwater, and more will redissolve as the phytoplankton consume the nutrients.

Thanks.I figured that's what was happening when the phyto exploded once I added the precipitated gunk. I also inferred that if I reduce the salinity enough, more ions would be released into the column despite all the other ions' interactions, like Sr,Ca,and Mg.
Does anyone really know what our detritus is composed of?

 

[bertoni]

Does anyone really know what our detritus is composed of?

Not in any detail.

 

[Dan_P]

As folks have mentioned, detritus is all kinds of stuff.

The organic matter in it that contains organic N and P will only release those elements as it is broken down, either by biologic action, or by abiotic degradation.

Measuring the water around detritus ought to be about the same as the rest of the water, because the release of N and P will be slow and steady, and it quickly diffuses into the water column as soon as it is released. But it takes a long time for it all to be released. Hence the concerns about detritus.

That said, I'm not hyper about detritus collecting in my tank. It let it collect all it wants in my sump and refugia. There's a thick layer in my sump, and probably more in my refugia.

If detritus is accumulating, it would seem that even the bacteria are not finding much nutrition in it. Has any one taken a closer look at this material? Is there more than one type of detritus, the material you should be concerned with and the material that is not much different from terrestrial dirt? It sounds like you have some fairly inert material. The thing I wonder about is whether there is a stage at which it becomes anoxic and becomes more dangerous than garden soil in the sump.

 

[Dan_P]

Did some cleaning of the sump earlier and decided to test the water that was drawn out using my little shop-vac. I passed it thru a coffee filter to remove suspended solids and performed a ULR Hanna test on it.

I first tested the tank water drawn directly from the tank and then tested the nasty, yellow-tinted water drawn from the bottom of the sump after I filtered it as mentioned.

Results? Both read the same 13ppb. Maybe another test would show different results of I let the detritus sit in the water for an hour or more? I think I'll test NO3 and see what results I get as well.

Question - if indeed detritus is filled with measurable organics such as PO4 and NO3, when or should I ask, how soon after, does it reach the water column? It's near impossible to extract detritus as it forms, so I'm questioning the common belief that detritus, if left unchecked and if my testing methodology was an accurate way to determine what is being released, should be such a concern.

I really expected to get different results considering the sludge I removed ( I generally do this once every two weeks or so ) was yellowed somewhat and had a large concentration of detritus.

One thing you might try for fun. Dry the detritus you have collected. You might find there isn't much solid material left once the water is removed. If true, it won't be much of a phosphate or nitrate source. I would be interested in the results, as crude as they are.

 

[boxfishpooalot]

It's not the detritus that's the main problem it's the bacteria that will degrade it releasing those nutrients. This is probably why the king of bare bottom (Bomber?) used a large uv light.

I once read that scientists found that seawater, thought to contain millions of bacteria per drop actually Had billions via electron microscope.

 

[Randy Holmes-Farley]

If detritus is accumulating, it would seem that even the bacteria are not finding much nutrition in it. Has any one taken a closer look at this material? Is there more than one type of detritus, the material you should be concerned with and the material that is not much different from terrestrial dirt? It sounds like you have some fairly inert material. The thing I wonder about is whether there is a stage at which it becomes anoxic and becomes more dangerous than garden soil in the sump.

I've not seen any analysis of it.

I expect that it is getting more and more processed all the time down to less and less digestable stuff. Detritus that has been around for a few years won't release much, certainly (yes, I have some of that ). Detritus that was fish poop yesterday likely will.

FWIW, I never remove detritus from my tank, and my sump has a thick mud layer of it. My regufia probably do too, but I can't see the bottom of them.

You just need to have enough nutrient export to keep up with it and it becomes a non issue (IMO).

It may become anoxic in some cases, and I agree that would be more of a concern.

 

[Paul B]

I think (but am not sure) that it is shells from pods (copepods and amphipods) which are crustaceans so they shed their shell which is not calcium so it will stay around a while. Also the hard parts of bristle worms such as their bristles. I know in my tank I have loads of pieces of crab and urchin shells or spines. Many algae's have hard calcium parts (I forgot what you call those) but most soft corals also have them that helps give them their shape. Fish scales and bones I would imagine also contribute. All of those things I mentioned don't sound like much but if you have an old tank, that stuff accumulates and the dead, dying bacteria and partially digested fish poop tend to bind it together until it falls apart and only the hard parts remain.

 

[Randy Holmes-Farley]

Such shells will be made primarily of chitin, which will very slowly biodegrade, releasing nitrogen.

 

[Paul B]

As I said, but you say it more elequantly with that chemist brogue

which are crustaceans so they shed their shell which is not calcium so it will stay around a while.

 

[tmz]

This question came up on another thread:

These are my thoughts and observations as noted there, fwiw:

I also have some detritus buildups which mineralize in my cryptic fuges and some sump areas . It doesn't seem to do any harm as it degrades there; however, if it builds in the display it fuels cyano ,nuisance algae and seems to be harmful to corals positioned near it,IME.



It does release nutrients as it degrades from hydrolysis as well as microbial and biotic activity occurring in a cascade with each digestion reducing the nutrient value of the remaining detritus , ultimately leaving refractory remnants which are of little consequence.
I think when the degradation activity occurs and it's by products go into the water in lighted areas they feed nuisance algae and cyano but some of that activity and it's by products may disturb corals if it occurs in close proximity to accumulated detritus ,IME.
So, I don't worry about it in the sump or cryptic refugia since it may be of use to many animals but do remove it from display tanks and grow out tanks, via brisk flow and/or occasional siphoning in areas where fresh detritus may be harmful to it's neighbors.