any tank mates? decoration? They're school fish and do better in group of 6. small discus seem like picking on other more than adult. I assume you just put them in new tank, if so, just leave them alone, they're figuring out territory/leader in the group. as far as feeding and wc, it all depends on what you feed them. Some breeders feed Beefheart and do WC constantly 100% or more. That does not mean you change 100% at one time. Ex: you can do 75% WC in the morning and 75% in the evening right after feed BH.