I use vita-chem, for a while I used Zoe and Zoecon. I switched to Vita-chem because it is suppose to be derived from natural sources (but who really knows). That has worked good for me, also make sure you vary your food. I have spectrum pellets, formula 2 flakes, mysis shrimp, brine shrimp, prime reef, formula one/two cubes, clam's, and cyclo is added bi-weekly to their food. Also, with a Moorish Idol, bristletooth tang, Naso, Magnificent Foxface and a soon to be added Orange Shoulder, I have to put Algae in the tank daily for the fish.