I have been fighting this for 4 weeks now. The fish store doesn't know what it is. At one point my Nitrate was very high, but now it's fine (10-20). Ammonia and Nitrite 0, PH 7.0. I've tried water changes, (4 gallon / 30 tank), and doubling up on stress coat and stress time. Did that for about a week. Fish store said I was doing too much, let it go. Cut back feeding every other day, stop the water changes. Did that, treated with charcoal to rectify high nitrates, also using Algone. I finally had to do a water change because it was so murky and ugly and it had been 2 weeks. Anyone have any ideas. I lost a couple of fish early on, but it's not impacting them. It's just UGLY.