TetraFin was the first flake food to be developed specifically for the nutritional needs of goldfish, and today is still the most nutrionally advanced food of its kind. TetraFin supplies goldfish with all of their nutritional needs, using only the highest quality ingredients and most advanced flaking technology, in a format that is easily digested, resulting in very little waste and maximum gain for your fish. Now with ActiveFormula for reducing stress and improving resistance.