pacu floatingup side down

Question
we lost power for about 5 hours so we were draining water and filling water at the same time he was doing fine we decided to go to walmart to buy a battery operated airator for oxygen when we got back he power was on and he was floating up side down still breathing ive tried holding him streight that works for a little bit then he swims does it again he is about 10 -12 inches thers is a coy in with him they have grown up to gether that is having no problems please help would hate to lose him

Answer
Sounds like swim bladder disease, caused by stress, poor water quality....and I'm guessing too small a tank.

Increase water changes to 25% every other day, add a little aquarium salt and feed him washed, shelled peas.

Out of curiousity...what size tank is he in? Pacus need at least 350 gallons each.

-Nick