HydroRemed for treating free product (fuel oil) in ground water. Usually, HydroRemed is added in the ratio of 1 gallon (3.785 Liters) of HydroRemed to 10 gallons (37.85 Liters) of free product. No addition of oxygen is required however where the groundwater is anoxic or contains limited oxygen, it is recommended that HydroRemed is saturated with air before release in the ground water. Tests have shown that bacteria are able to survive in a healthy state for one week in waters of low oxygen levels when HydroRemed is saturated with air.