I have a small number of RES from this years hatch in my aquarium. I have been running the Optimal through a coffee grinder then sifting the smaller pieces out through a strainer. The larger crumble pieces I am feeding will float for a little bit then slowly sink as they hydrate. I have done the same thing with Aquamax in the past and I can tell you that my RES definitely prefer the Optimal. When running it through the grinder both types of feed come out in the same random sizes and shapes.