WC are the best way to keep the parameters in check. If they have ick, how are you treating them? I would do hyposalinity before copper. If you choose to do hypsalinity, it can only be done with fish and you should take anything else living out (rocks, sand, inverts, etc). If you can, do the changes every day after you have fed them. That way you can get out as much left over food as possible.