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.

[bertoni]

It might be removing some nitrate by harboring microbial films. On the other hand, at some point, it might start generating a lot of hydrogen sulfide, which could be toxic. It also might generate some nitrate, although that could be measured. I'd probably remove it out of general caution.

[slapshot]

Thank you, that was my thoughts but just wasn't sure. I know it defies conventional wisdom I just wondered if anyone had tested its nitrate removing capabilities.

[Bigcefa]

Have you checked out biomate from zeo , should help with that problem

[bertoni]

I don't know of a good way to measure the nitrate-reducing effect in real life, given hobbyist equipment and cost constraints.