Pond Medic Malachite Pond Medic Malachite is an effective treatment against many ecto-parasites such as Whitespot, Flukes, Ciliates and Flagellates. This product is of the highest quality and is totally Zinc free. Note Do not use below 14 Degrees C. Always mix in a suitable container with some pond water and distribute evenly around the pond. For severe cases use as a dip at the rate of 1ml per 5 Litres for up to 30 minutes maximum followed 48 hours later by a standard treatment. Use in conjunction with Kockney Koi Formalin.