The Pettex Premium Variety Pond Mix Sticks are suitable for all coldwater fish, including Koi, Orfe, Carp and Goldfish. The special formula keeps fish healthy and gives them all of the protein, fibre, vitamins and trace elements which they require in order to maintain great digestive and immune systems. The pond sticks' natural shapes ensure that your fish feed eagerly, and the balanced formula means that you don't need to overfeed them, thus reducing water pollution and ammonia build up.