Easy to over feed when first starting out. This happened to me a few years ago but my out break was planaria worms. Took forever to get rid of those damn things. I run a large sump and used filter padding which allowed food and junk to get in my bio media. I switched to 50 micron sock filters and started a bio cleaning regimen to get rid of them. Sounds like you need to cut down on feeding and get you a cleaner fish.
