hello in my 20g tank we just got 2 convicts.they dont seem to like the pellets i give them.they are not the smallest but are the next size.i am new to cichlids what else do they eat?i gave them some of tropical flakes from the other tanks and the female eats some but the male eats it but spits it out.what else could i give them?and is there anything that i should know about cichlids?thanks