I find when my SG is a little too high that my starfish climbs up my glass then jumps to the bottom. This has only happened 3 times to me but everytime after I was doing maint and found that the SG was a little tiny bit too high. Check your sg and keep in mind that the starfish may be doing his dead poets society impression. If you hear "Oh captain, My captain" each time he gets up there then grab some popcorn it was indeed a great movie.