Carophyll yellow is an extremely effective color enhancing food additive for aquarium and pond fish. Wether you keep discus, koi, African cichlids, live bearers or anything in between this product will have a positive effect on their yellow colouration. A little goes a long way with this product. The dosage is 1/4 teaspoon per 1 lb of food. This product is not a hormone and won’t harm your fish. This product ships for free within Canada and the USA. International shipping is $15.