From what I was told, you are suppose to be able to stick the cubes to the glass, and the fish will eat them up. I got this when I had a couple gouramis. It never really stuck though, but eventually breaks apart. It just a bunch of worms stuck together in a cube, I use it to feed my African clawed frogs. And I have been using Omega One since I started reading the ingredients on the back, Omega One is the best by far.