I noticed my blue tang, which I've had for 4 months, just wants to hide in the rocks all day and wiggle around. It's been doing this for about a week now. I have been breaking my brain trying to figure out why. Doesn't seem to be eating. When it does leave the rocks, it looks very stressed and starts bouncing off the glass until it retreats to his hiding spot again. Any ideas what's going on? Constipation? Fluke's? (I tried a 10 minute freshwater dip - no change)