Coral Feast is milled in a FDA certified factory and is milled  and sifted with a 300 micron screen leaving a  300-500 micron particle size making this ideal for all  NPS, LPS and SPS and sponges and clams.  It is small enough to aid in the digestion so they absorb as much nutrients as possable, also making them excrete less. The milling removes  all of the impurities, making it cleaner then any other coral food.