I have had a 5 to 6 inch hippo tang in my 210 reef for several years and every night after feeding for about fifteen minutes this fish goes to the surface and takes in a big gulp of air. Then he swims off releasing little air bubbles. This is not really a big problem but at least once or twice every night he will make a big enough splash to make water run over and down the outside of the glass and I find myself cleaning salt off the outside of the glass. Hence the problem. Not fun every day. Any thoughts?