200 gallon marine reef. about 7 years old. soft corals only. very low fish load. recently introduced a new powder brown. normally I fresh water dip follwed by QT for 10 days with methaline blue and melafix or some other antibiotic. this time I skipped the fresh water dip because I wasn't sure how delicate they are. about 10 days after and once he was really eating well (having tug of wars with the yellow tang over seaweed) I noticed all the fish lining up in front of the cleaner wrasse. They usually pay him no mind for the most part. I noticed some increase in itching. They were all eating well. Then the powder brown who had eaten well in the morning was dead when I got home from work. the only signs of disease are their actions and some cloudyness on the coral beauties eye. If they are in just the right light angle I can maybe see a film on the skin but its very difficult to see. I did a 1/3 water change and lowered the salinity. the ph, ammonia, etc. all check out fine. thought I might have flukes so I dosed on Monday with prazipro and then again on Saturday and started up my diatom filter. no carbon. no skimmer. on Thursday did a 50% water change, started carbon and skimmer. diatom still running and recharged. its been a week since and they are still itching and asking cleaner wrasse for help. he's itching too. all are still eating but seem stressed and cranky. thinking of getting a uv sterilizer. Any ideas?