Hi all i have 2 sting rays and 1 clown knife fish the rays are 7-8inch & 9-10inch the clown knife fish is 8-9 inch and there not really getting along anymore as the and they have had there battels ( the rays are winning at the moment by pinning the clown down. he has 2 like ring marks (bite marks) at the moment so anyway ive been thinking about swoping the clown for a gaint gourami and just wonderd wot peoples thoughts were as a tankmate? 0r if anyone keeps or in the past these 2 together.