brown residue in reservoir

Battlecorals · 2026-10-04T09:53:48-0400

Cleaning my reservoir this weekend and the brown stuff has been really stubborn.

I’ve got about 2.5 bottles of 10x vinegar in there and roughly 200 gallons since Friday and it hasn’t really done a thing

Wondering if it just needs more time or if there is a better way

This was before I added the vinegar

jonelder68 · 2026-10-04T10:13:00-0400

Citric acid does the job usually. If not and you feel comfortable Muriatic acid cleans the best! Citric acid always works for me but sometimes requires some elbow grease with scrubbing.

Fish Fan · 2026-10-04T10:22:33-0400

I've never tried vinegar for the brown sludge, but I wouldn't expect that to work. I find I have to scrub the brown sludge out of the bucket.

Battlecorals · 2026-10-04T11:08:22-0400

jonelder68 said:
Citric acid does the job usually. If not and you feel comfortable Muriatic acid cleans the best! Citric acid always works for me but sometimes requires some elbow grease with scrubbing.

yeah I should have went with citric friends suggested that as well. the vinegar was at my disposal so I used that instead lol. I have been pressure washing the walls as well with little progress there either. almost like its permeated the actual plastic. is that possible

jonelder68 · 2026-10-04T12:11:35-0400

Battlecorals said:
yeah I should have went with citric friends suggested that as well. the vinegar was at my disposal so I used that instead lol. I have been pressure washing the walls as well with little progress there either. almost like its permeated the actual plastic. is that possible

Citric acid should remove it all. Sometimes it takes a scrubbing followed with more soak time. I’ll usually fill my bins with tap water. Add citric acid. Throw in some powerheads/pumps that need cleaning and let them run to keep water movement. Runs over night. Then do a scrub and continue running everything. By days end it should all be cleaned. Then just a rinse in rodi for everything and good to go. Everything comes out new looking/sparkly clean. It takes a bit of citric acid to fill a reservoir though. I’ll just buy a bag off Amazon and throw it in.