my sailfin tang is staying on the bottom of the tank breathing hard, not really controlling where he goes, sometimes going nose does or upside down. Yesterday he was doing great, eating, swimming. Today he won’t eat and doesn’t look good. No color fading, still looks healthy weight wise. I did a lot of research and nothing seems to look or act like what I am reading. I thought it might have been flukes so I fw dipped him but didn’t notice anything coke off except for a white spot that was on his tail. Any idea of what could have caused such a fast decline or what do to going forward. Other fish in tank are 4 clowns and a social wrasse.