Very true!! This can be basically said for most "reef" fish as that's the nature of the reef, in n out during the day feeding, hiding at night. I had gotten a container of these http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=27344 but once the fish get about 3/4s the way thru, it falls off and a big chunk goes floating. I didn't care for that, but I like the idea. My next step is the new innovative marine grazer for the tangers.