What’s the brown gunk in my sump?

[Miami Reef]

There’s a brown gunk that accumulates overtime in my sump. It mainly collects inside the skimmer, return pumps, skimmer body, and skimmer base.

I skim, filter with 100 micron socks, carbon dose (vodka or vinegar), use activated carbon, and ozone.

It looks gunky and organic in nature, and it wipes off pretty easily. It’s a little sticky.

Does anyone else accumulate it? It doesn’t bother me. I cleaned out my sump today, and the last time I cleaned it was last year.

 

[EeyoreIsMySpiritAnimal]

There’s a brown gunk that accumulates overtime in my sump. It mainly collects inside the skimmer, return pumps, skimmer body, and skimmer base.

I skim, filter with 100 micron socks, carbon dose (vodka or vinegar), use activated carbon, and ozone.

It looks gunky and organic in nature, and it wipes off pretty easily. It’s a little sticky.

Does anyone else accumulate it? It doesn’t bother me. I cleaned out my sump today, and the last time I cleaned it was last year.

Yep. Idk exactly what the makeup is, but it's not harmful to anything...

 

[Miami Reef]

Yep. Idk exactly what the makeup is, but it's not harmful to anything...

Thanks. I assumed it wasn’t harmful, too. I was just hoping to limit it, but I think it’s just accumulated fish poop. Nothing bad. I can clean it once a year with no problem.

 

[Pod_01]

There’s a brown gunk that accumulates overtime in my sump. It mainly collects inside the skimmer, return pumps, skimmer body, and skimmer base.

I skim, filter with 100 micron socks, carbon dose (vodka or vinegar), use activated carbon, and ozone.

It looks gunky and organic in nature, and it wipes off pretty easily. It’s a little sticky.

Does anyone else accumulate it? It doesn’t bother me. I cleaned out my sump today, and the last time I cleaned it was last year.

It might be some bacteria strain that likes your carbon dosing source….

If fish poop, that falls under detritus. But your socks should get most of it before it gets further in the sump.

 

[Randy Holmes-Farley]

I agree it is likely a biofilm of organisms, maybe also including accumulating detritus in it. I wouldn't try to remove it unless it is an aesthetic problem.