Pond HealthGuardT is a safe disinfectant to promote the control of parasitic, bacterial, fungal, and viral infestations in ponds. It contains no malachite green or other dye based disinfectants that can discolor or quaternary disinfectants that foam. Used as directed, it is safe for fish, plants, and the biological filter. A 2 Liter size treats over 4,000 gallons.