Oh forgot, put an algae tablet down after lights are off for the cory's. They will get it then without a fight. Also, try feeding warmed, deshelled pea's, smushed up a couple times a week. You don't need many. My rams love them and the cory's do too. Actually all my fish, angels, rams, tetras, cory's, loaches all love pea's. And with peas they can take pieces and run with them.