Anti-Parasite and Fungus Mixture of Malachite Green and Formalin formulated for treating sick Koi with a parasite or fungus infection. FMG provides the same treatment levels as the two individual components used separately. A ready mixed Koi treatment eliminating the need to mix separate treatments, the treatment levels are higher than other proprietary mixtures which means this product should not be used when sensitive fish such as Golden Orfe or Sturgeon are present. FMG can be used where Goldfish are present.