He might be getting parasites in that gill since the cleaner shrimp isn't there to clean him any more. If the cleaner shrimp died of natural causes get another one for your tang, since they form very symbiotic relationships. If the shrimp died from something specific fix it and then get another one. Also are you feeding supplemental marine algae (the good stuff you have to pay for, not the nuisance algae) and high quality food to him?
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55gal,216 watt Tek T5, 45#LR, 45#LS, 3 maxi-jet 900's on a natural wavemaker timer,phosban reactor, 5 gal fuge (built out of standard 10 gallon tank) with chaeto and feather caulerpa, sealife systems protein skimmer, wet/dry, 3 blue/green chromi, 1 skunk cleaner shrimp, 1 coral beauty,1 scopas tang, 2 false percs, 5 mexican turbo snails, assorted dwarf blue leg hermits, astrea snails, and nerite snails |