Clownfish swim bladder?

Hi, my clownfish has been staying close to bottom, swimming little erratic and was sucking air (thought it was my intank light that had moisture in the lens so got rid of it) She wasn't eating so I have moved her to small QT tank and see she is moving with no problem now... it has only been overnight. I planned on not feeding her for 3 days then giving her shelled peas... I read about Epson salts but not sure if should be a bath or is okay to put in and keep it in the QT tank.
Any suggestions?