Optimal food source for all species of Marine Tangs, Angels, Wrasses, Damsels and some Butterfly Fish. Brown Marine algae is a nutritious supplement for all grazing fish, rich in vitamin C and is 100% digestible. Optimal food source for all species of Marine Tangs, Angels, Wrasses, Damsels and some Butterfly Fish. Nutritional Combinations: This product should be used as a supplement to other food sources. We strongly recommend Formula Foods (Formula One, Formula Two, Brine Shrimp Plus, Spirulina Formula, etc.) and Aqua Yums (Bloodworms, Brine Shrimp, Squid, etc.) from Ocean Nutrition.