I purchased a foxface one spot for my 150 and it looked healthy wouldn't eat, and got stuck to the powerhead freed then died two days later. I told the fish store that it should of been strong enough to pull away so they replaced it with another one well it is acclimated and wont eat it is 3 days later and I have the powerheads unplugged out of fear what do I do? tested parms and everything is in check and all the other fish are eating like pigs ...hippo tang, 6 line, bi color pseudo, and blue spot blenny