"You should try changing out a portion of the water. Ammonia from the fish's waste can build up in the tank, which a filter only partially solves. Remove about a third of the water in the tank and replace with water that is lukewarm or colder."@en . "You should try changing out a portion of the water. Ammonia from the fish's waste can build up in the tank, which a filter only partially solves. Remove about a third of the water in the tank and replace with water that is lukewarm or colder."@en . . . "Our pet gold fish is only slightly moving he is lying near the bottom. Is there anything we can do"@en . .