I have a 90 gallon reef tank with a sailfin tang, blue hippo, yellow tang, powder blue tang, 2 engineer gobies, 2 clowns, and 5 chromis. I had the 2 clowns and a dottyback (died today) for a week in the new 90 before i put in the gobies tangs and chromis. I had the clowns and dottyback in my 28 gallon for over 2 months. Two days ago I noticed my orchid dottyback had a bilge in his stomach area and thought it was normal because he was eating like CRAZY and was very active. It kept getting bigger and bigger and this morning it had raptured his skin and he died . I noticed that one of the chromis has an open sore in the fin area and part of his tail is "eaten away". I got the tangs gobies and chromis on last wednesday and I picked up a huge elegance coral last Saturday. 3 days ago when my clowns started sleeping in the elegance (so cute!) i noticed an open wound by the fin of the female clown. It was deep and looked as if it was a cut from brushing on a rock or something. Its healed a lot on its own but I noticed the male a couple days ago lost some of its coloration in the same area as the female but as of today it hasnt gotten worse. The chromis and the two clowns are acting completely normal and are eating like crazy. I have NO idea whats going on and I don't want this to progress and infect other fish if its bacterial. My 4 tangs area doing amazing and eating like beasts( romaine lettuce, mysis, and pellets) all my fish are acting normal and as if they werent sick but the death of the dottyback and the weird wounds on the chromis and the clownfish are REALLY starting to worry me! I don't runa UV sterilizer but i have a aquacremora protein skimmer and a phosban reactor. My parameters are Ammonia 0 Nitrite 0 and nitrate less than 10. All the parameters are fine. Thanks in advance for replies!