Look very carefully on the yellow tang for ich. Look sideways along the body as it is sometimes hard to see on a yellow tang. I would start feeding garlic extract now.

Trigger, barring water quality problems, your experience with the achilles is typical. They do fine for a while than up and die for no apparent reason.

Jason How's the tang? How's the bubble? Everything okay?

Thats what I thought too with the Achilles, but then a few hours later my Kole started showing the same symptoms so I medicated him in my QT and he is looking better today. Both of the affected fish were tangs and I had put new corals in the night before, which they had picked at. Hence I believe the coral or rock brought something with it.

Hi Carmen, the Tang and the coral look great today. I am not sure what happened with the tang, I pointed the powerheads up for more surface agitation and am running carbon today, and all seems well. The coral looks awesome, it even ate tonight!

I didnt notice the tang nip at the bubble coral, but definately could have. I feed Michika's food, so they get garlic almost every day. Anyways, all seems to be better, thanks for all your replies, greatly appreciated!

Glad to here the problem has gone away. Always a little stressful when you know something looks off but you can't figure it out.