I work at a LFS and it seems like we are having a constant battle with ICK and other parasites. No matter what we try and do, we have fish losses. We have tried using a copper based system using just an ammonia tower and a skimmer, switched to a sump with roughly 200+LB's of sand and cheato with a skimmer, but still we have losses, its becoming very stressful on us no matter what we can do we cannot combat it. It really seems like no matter were we buy our fish from we still have this problem, we have also tried different measures of acclimating the fish and still havent saw a change. Tried running our salinity a bit lower and that did not help, also running a UV on the system, If anyone has come up with a way that has decreased this problem or any ideas let me know! Thanks!