Malachite Green is a chemical dye with antimicrobial properties to help fight disease. It has many uses from treating external parasites, such as Ich, in both freshwater and saltwater environments as well as treating certain fungal diseases. Egg fungus, Ich and other common external parasites, oodinium (Velvet), Saprolegnia.
 
Treatment:
Bath:  Add 1-2 mg/l for a 10 minute bath; or 0.5 mg/l for up to an hour. Monitor fish closely and do not exceed the time limit for the strength of bath.
 
External Parasites: Mix with formalin to create your own treatment. Mixing 3.68 grams per liter of formalin to mix a solution. Then dose at 5 drops per gallon.
 
Stock Solution: Add 3.5 grams per liter distilled or RO/DI water. Dosed at 1 drop per gallon. Repeat every other day for a max of 3 doses. Before each dose do a 25% or greater water change. Use caution when dosing as this chemical dye can cause gill issues when overdosed. Malachite Green can stain seals and tank glass. Use caution when treating a display tank.