Help please!!!

[anaitari]

I just picked up a small blue tang and acclimated him for a few hours before adding him to my tank. He seemed great during this process. I iadded him to my tank and he swam at the very corner for a few hours so I thought he was just getting used to things. I thought there was too much flow for him cause he was so small so I turned off one of my powr heads . He swam down but keeps floating to the top. He really has to fight to stay down. Can anyone help me and let me know if theres anything I can do, He doesn't look so well and I don't want to lose him