thank you guys for helping me with getting my tank to where it has to be. also thanks to those who helped on aquaria central forum, but my computer hasn't allow me to get there lately. i apritiate everybody's input and share of the experience. my yellow tang was sick, but looks great now and eats like a horse. i didn't think he was going to make it, so i'm very happy that he made it. it was a long way to a recovery for him. my corals also look better and bigger. i used everybody's input for my yellow tang and he responded. thank you all greatly. :rollface: