I have a 10 Gallon Fish tank wherein I had a couple of Firemouth cichild and Walking catfish. Since the catfish and Firemouth grew, I had to give them away. I gave them away yesterday and in place added some small yellow morph. Today morning I found all the morph were lying dead. There is no other fish in the tank.
What could have caused this. The Old fish were healthy and good. I am not sure what could have happened or what have I missed. I am now planning to completely clean the whole tank and start afresh. After this incident, am a little scared to add new fish. What fish can I add to the tank and what should be done to avoid such incidents.
