i have the skimmer on now and added some polyfiber pad to try and absorb any particles that may be from carbon. skimmer is pulling out some nice foam. as far as the tang it is starting to swim out from the rock but not active as it usually is. but it is not hiding any more. what concerns me is it is still breathing rapidly. none of the other fish are breathing like that. i'm also noticing one eye cloudy on my brown tang still. no spots or scratching on rocks so I don't think it is ick. i bought some melafix and may treat the yellow tang tomorrow it it doesnt start to eat. it's been about 4-5 days since I've seen it eat. it is usually a voracious eater at anything i put in tank. both tangs have stopped eating the dry seaweed altogether which isn't usual for them. i hope the brown tang continues to eat. what else do you think is going on in my tank.