Just to make sure, please describe how you clean your filters. You don't want to be too aggressive with bio-media, but you can replace mechanical as a general rule.
NorCaliCichlids;3695326; said:Depending on how the pitting is here is my full proof solution. catch the oscar and poor a small amount of metro directly into the pits and make sure its in the pits pretty good and put the fish back in the tank. Do it 2-3 times like that and do what else you've been doing. I learned this from an old LFS owner here in cali. Works every time. That's what I would do to be sure.