He is eating glitter? Just remove any that has gotten into the tank as soon as possible and be more careful that nothing will fall in in the future. I don't think a fish would be likely to actually consume glitter.
I cant even begin.... why in the name of.... glitter? ok I have to ask. why would you put glitter in your tank? check and see what its made of and get back to us. and like falina (still doesnt sound right :P) said, dont put any more in