I had a death in my tank last week randomly and I have had another one this morning. I dont know what is going on but some of my fish are staying near the surface of the water. 1 is sitting on the bottom of the tank. Some are breathing hard and flickering there fins. My water parameters are nitrate 0 nitrite 1 ammonia 0 ph 7-7.5. I dont know what to do at this point but multiple fish are affected and I'm greatly concerned. Looks like someone is shedding there slime coat. I need suggestions ASAP!