My clown fish has been very happy in my tank. He is the only fish in there with just a cleaner shrimp and some corals. He always use to eat the pellets I fed him and use to go nuts about them. Then about 5 days ago he just stopped. He watches them fall to the ground and if he does eat it he will eat it but spit it back out and not try to eat it again. It's the same food I have been feeding him since day 1. He also has been hanging out towards the back now. I also tried flakes and brine and mysis same thing. I also noticed this white stringy poo coming out of him. Help.

