<a href=showthread.php?s=&postid=12515028#post12515028 target=_blank>Originally posted</a> by OceanSpray
Tangs can be very sensitive to low oxygen levels. When my power went out, my other fish seemed fine, but my yellow tang was on his side gasping, until I got my generator going. Maybe somehow the new system isn't putting enough oxygen in the water? Just something to check. Good luck with him!