I woke up this morning to see my clown fish hoovering over the sand at the bottom of the tank. hes been there the entire day and still there. I don't notice anything different physically on him, no mucus or white spots or anything. The only thing I did was change my water yesterday and bumped the salinity up to 1.025 from 1.023 and he was fine after the WC. What could be wrong? All parameters are good. Nothing much changed. I feed every other day with half a cube of mysis, I only have 2 clowns.