Please help! I have a black ghost knife fish in a grow out 55 gallon tank and it seems to be sick or something. You see, im 13 and i had to go to my brothers hockey tourtament this weekend, and i put it in my brothers tank. Which is also 55 gallons. We have the same water paraments (Ammonia 0 ppm nitrites 0 ppm nitrates 0 ppm ph 7.6) however, one of his angelfish died over the weekend and i believe that raised his ammonia, and im worried my bgkf has ammonia poison. I already did a huge 75% water change, but she is stll acting wierd. Shes trying her best to swim, but she can barely move. Its almost like shes crippled. My brothers tank has 5 angel fish a bristle nose pleco, and a small silver arowana( that tank is just for now the arowana will be going in a 180 gallon) i have 3 2in clown loaches and 4 3in silver dollars. Does anyone know what to do? I really dont want to lose this fish