My 55 Gallon tank water keeps turning brown, in a matter of days, so brown that if somebody told me it was liqueur I would believe them. But its only been happening recently, I recently took in quite a few fish from by buddy who was getting deployed to Afghanistan, I had to re-home them as they were all too big for my tank (3 x 5" oscars, 3 x 5") I figured that had to be what was doing it, I found them all new homes, did a 75% water chance, changed out the filter carterages and a few weeks ago even bought a UV sterlizer, same thing. None of my other 4 tanks are doing this, theyre all crystal clear.
The current stocking:
1x Dojo Loach
1x Peacock Eel
1x Bala shark
thats it. I dont understand, every water change its clear, but within 2 days its terrible again.