I am new to the site and dont know where else to go for help. I have a 65 gallon fresh water aquarium. In it is 4 goldfish, one is 1.5 inches, ones 3 inches and two are 4 inches and a 4-5 inch pleco. One of my goldfish has shown signs of ammonia poisoning. I had rushed to the pet store and bought some ammo-lock. Once home I tested the water everything seemed fine but the ammonia and nitrates or nitrites were just a little bit over 0. The lady at the pet store had told me to do a slight water change about 20-25% and to use ammo-lock as directed. My poor goldfish seems to be going downhill fast and I dont want to lose it yet! The poor thing has had 2 close calls so far and I'm not going to let this be the last. I'm worried the oxygen in the tank might not be good enough. I have pictures of the condition of my goldfish and a picture of my tank with the bubbles from the filter. I had taken the goldfish out gently with a net and put him in a small container because he just lays in the bottom and doesnt move. Now in the small container I just put a little bit of stress coat to help with the white marks on him and he seems to be moving in the container more than he does in the tank. Any help would be GREATLY appreciated!