My jewel cichlid spending most of its time at surface like it would when gasping for oxygen. But don't seem to be gasping. Been like this three weeks now all fish in the tank are healthy and going at there normal business. Water is fine. And water changes have been done as normal.there is no visible problems on the fish he looks healthy. He is 4 years old not sure if age is anything to do with it but thought I would put that in just in case. If any ideas please help.