I have had the powder blue tang in a stable water conditioned 85g tank for 11 days and there is no evidence of it eating. I have tried fresh nori, dried nori, frozen brine shrimp(thawed). There is some hair algae growing in the tank. At purchase, it had been in the LFS for 3 days and hadn't eaten there either. It was in perfect condition and now looks slightly concave in the cheeks. Over the last two days, it has developed small lumps behind its eyes on the powder blue surface (paracites?) What do I do? I have no UV facility at the moment.I have lots of inverts and am concerned about their welfare if I start adding chemicals. Should I phone the LFS and ask them to take the fish back? It cost me £45 which is about $66. The money is not the major problem. I dearly want to save the life of the tang. The two clowns are doing well. I really will appreciate some sound advice. I think I have probably made a poor choice in purchasing a powder blue after only 12 weeks of setting up the Berlin system.