So I recently got a 200 gallon tank and stocked it with a pair of clowns a fox face rabbit fish a lone mower blennie and a sail fin tang. The first day I put the sail fin in the tank I realized some white spots but after a few days they went away full so I thought it was fine. Fast forward a week and he died of marine velvet and now my fox face and clown have marine velvet so I’m going to try to put the fox face and clownfish in a qt tank and run copper threw it but what should I use?, what should I do with my shrimp, crabs and snails and what should I feed the sick fish while treating please someone help