Hi I have gone to my tank and found my powder blue dead on the sand. I have took him out of the tank when I have looked at him he as blood coming from is gills. I have never seen this before on a fish why as this happened, can anybody please help me. I have done a test for ammonia and it as come back clear. I am gutted as he was a stunning fish and one of my favourites in the tank. He was feeding yesterday and swimming around like he normally would.