Kaycy, Thanks for your reply. I'm thinking that there may not have been enough circulation in the tank (Eheim cannister filter). When I took out the driftwood, it smelled like sulfur. This may have collected in the substrate which is 3-4". The tank has been set up for 3 months beofre that it was a Tanganikan tank. I will give what you said a try, that is test out with some less expensive fish. Thanks again. Andy