Lets talk mulm!

[slapshot]

So I spent the day cleaning my sumps yesterday. As you can imagine I cleaned quite a bit of mulm from the bottoms. I normally do this monthly but one of my sumps had accumulated over an inch of the stuff. So I carefully removed it and dosed the sump with potassium permanganate. I do this every time to avoid any issues with hydrogen sulfide. All is well.

It occurred to me that maybe removing this layer is not a good thing. Wouldn't this layer, in a slow flow sump, be removing nitrates? isn't that why it smells like hydrogen sulfides? So should I let it be or keep removing it? Any discussion would be appreciated. Thanks.

[MizTanks]

What is Mulm?

[jasper]

Yes it seems that theoretically it should be removing nitrates but there is always the dangerous possibility that it could be disturbed, I assume your not using any sort of mechanical filtration between your display and sump, a sock could catch most of that, my sump is bare and only has spots of detritus(mulm?) and it's been running for over three years, have never cleaned it out

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[slapshot]

What is Mulm?

That crap that builds up....literally

[slapshot]

Yes it seems that theoretically it should be removing nitrates but there is always the dangerous possibility that it could be disturbed, I assume your not using any sort of mechanical filtration between your display and sump, a sock could catch most of that, my sump is bare and only has spots of detritus(mulm?) and it's been running for over three years, have never cleaned it out

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I have several sumps two that are slow flow, deep sumps. The slow flow deep ones build up the most. I don't like socks because I want the food floating around for my NPS. That said, I still wonder if it is removing Nitrate and if so it should be good. Until it get disturbed that is. Assuming it does not get disturbed what ids the downside of having it?

[binford4000]

This is a good question. Although you have a diffrent situation then most due to the feeding regiment allot of your corals need. Personally I am going to go on the limb and say removing it once it accumulates as you are is probably jump starting your bacterial activity. Yes I think it could be removing some issues but eventually the hazards would out weigh the benefits in a very deprivental way. Of course this s just me jumping in and and truth be told if I was contemplating this with my system I would do a study of both situations to derive my conclusions. :oldman:

[slapshot]

This is a good question. Although you have a diffrent situation then most due to the feeding regiment allot of your corals need. Personally I am going to go on the limb and say removing it once it accumulates as you are is probably jump starting your bacterial activity. Yes I think it could be removing some issues but eventually the hazards would out weigh the benefits in a very deprivental way. Of course this s just me jumping in and and truth be told if I was contemplating this with my system I would do a study of both situations to derive my conclusions. :oldman:
I'm pretty sure I agree with you, which is why I remove it. It just occurred to my as I was removing it yesterday that maybe I should be keeping it. I wonder if it is creating nitrate or removing it.

[binford4000]

Well since poop and decaying food makes ammonia and No3 consumes ammonia I would guess it creates ??? Man I feel like I am playing are you smarter then a 5th grader! Lol

[slapshot]

Well since poop and decaying food makes ammonia and No3 consumes ammonia I would guess it creates ??? Man I feel like I am playing are you smarter then a 5th grader! Lol

I think we are!!!

[Sir Patrick]

I cant see any way or reason this could or would be beneficial. Remove it.......mulm, to me, seems to be nasty uneaten. breaking down, PO4 and NO2/3 causing crap.

I dont see any way its any different that any build up we get on our sanbed or our bare bottom tanks.

I have a feeling this "mulm" might be, in the back of slapshots mind, for converstion and some input on thoughts of the minds of many reefkeepers, be compared to a deep sand bed, in one way or another.

I know it got my mind turning.

Just in case, i will skip to a main point- The mulm on your sumps bottom is very disimilar to a deep sand bed and its bethnic zones, and will do nothing but bad accumulated in the bottom of your sump.

In my point of experiance, the Mulm is nothing more than the same buildup on your bare bottom tank or sandbed in a tank without enough fow to get the "crap" to settle in the sump, which is removed religiously by most of us.

Great topic though Slapshot. This post had my gears turning for a while, just to make sure what I replied was what I thought correct! Had me wondering for a bit!

I am confidant in my opinion, but looking forward to what others think on this subject.

[jasper]

I cant see any way or reason this could or would be beneficial. Remove it.......mulm, to me, seems to be nasty uneaten. breaking down, PO4 and NO2/3 causing crap.

I dont see any way its any different that any build up we get on our sanbed or our bare bottom tanks.

I have a feeling this "mulm" might be, in the back of slapshots mind, for converstion and some input on thoughts of the minds of many reefkeepers, be compared to a deep sand bed, in one way or another.

I know it got my mind turning.

Just in case, i will skip to a main point- The mulm on your sumps bottom is very disimilar to a deep sand bed and its bethnic zones, and will do nothing but bad accumulated in the bottom of your sump.

In my point of experiance, the Mulm is nothing more than the same buildup on your bare bottom tank or sandbed in a tank without enough fow to get the "crap" to settle in the sump, which is removed religiously by most of us.

Great topic though Slapshot. This post had my gears turning for a while, just to make sure what I replied was what I thought correct! Had me wondering for a bit!

I am confidant in my opinion, but looking forward to what others think on this subject.

But if he has absolutely no mechanical filtration it's not just detritus accumulating...just to be devils advocate wouldn't the "mulm" eventually layer as it does in a deep sand bed after time...if there is fine arogonite(sp?) also resting in the sump?

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[Tom@HaslettMI]

I'm in the remove it camp. However, I have heard that it's similar to (and can serve the same purpose as) the "mud" that is sold for refugiums. Perhaps you should throw a light and some macro on it an see how it goes!

If you really wanted to find out you should do some water testing. If it is a slow flow sump (may be?) test the nitrates in the main tank and in the sump. If there's any difference than you have your answer.

Tom

[Sir Patrick]

Jasper-

Definitely some thoughts to ponder.

[jasper]

I'm in the remove it camp. However, I have heard that it's similar to (and can serve the same purpose as) the "mud" that is sold for refugiums. Perhaps you should throw a light and some macro on it an see how it goes!

If you really wanted to find out you should do some water testing. If it is a slow flow sump (may be?) test the nitrates in the main tank and in the sump. If there's any difference than you have your answer.

Tom

I agree, in fact I'm in the camp of preventing it to begin with....but for arguments sake: as you said it does seem similar to a ecosystem type model (mud refugium)

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[dputt88]

remove it! you likely have many other places in your tank that have all of that bacteria in it.

i would say this is not like mud, there are several reasons why many people use mud in refugiums such as it consists of very small particles, meaning more surface area meaning more bacteria. secondly the small particles become more compact and there is less water movement therefore creating an anoxic zone with less depth. also people use them for seagrasses and mangroves because these plants have true roots unlike macroalgae, plants with roots use them to take up mineralized elements that will be plentyful in refugium muds.

the mulm is different from the mud as its is made of loosely packed organics and it to my knowledge does no serve any of the benefits of mud though they may seem simular.

mulm may contain bacteria, but its also an excess of nutrients for the bacteria ( NO2/3 and NH3).

so to some it up, im in the remove it camp.