Hey all,
Seems I have something going on with my fish. I have been losing one or to small tilapia a week for the past few weeks. The first four or five showed no signs of disease but the last two have had eye bulge and now I have two that are swimming around slightly tilted to their sides. I caught These last two and they appear visually ok but have a feeling morning will bring bad news.

Water has been fairly consistent over the past four days, 0 ammonia, 0 nitrites and as of today nitrates are 0. I have several water changes lately due to high nitrite. I had been running consistent at 1.6 on nitrites and my last water change took care of that but has also knocked out my nitrates.

Any pointers or ideas? I am starting to wonder if there isn't enough oxygen in the water.