I have a 75 gallon setup that I bought used. So far the only inhabitants are a fox face, a damsel and two clowns, with a few snails. Had a butterfly fish at one point that introduced ick to the tank. I have since set up a small quarantine tank and managed to get the clowns under control however catching the fox face and damsel is a nightmare. I would like to find out how to keep this tank from getting ick again without completely ruining it. I’ve been advised not to add copper to my main tank and I will be setting up a larger (40 gallon) quarantine for my larger fish and let my display tank sit for a few months without fish. Is there anything else I should do? I am hoping to get a juvenile blue tang and eventually upgrade my tank to 125 or 180 gallons but I won’t be able to keep one alive if I keep struggling with ich.