i have 8 green sunfish in a 29 gallon long with 2 channel catfish and 1 pleco(they are all foing into a 300 gallon pond next summer and the big green sunfish keeps swimming over to a rock in the tank,turnng him self onto his side,and then hitting the rock really hard and they're all starting to do t now is someting wrong with the water?paracites?i really dont want him to die please help!