Rabbitfish such as Foxfaces often eat it, as will Desjardini Sailfin Tangs, but individual fish vary, more so with the Tangs. Rabbits are pretty reliable Valonia eaters ime.
hemostats do an excellent job, but if you have enough tank for it...Red Sea Sailfin tangs love the stuff. I've also heard foxface rabbitfish will eat it as well.