We do not recommend using Pet Water Additive with your pet’s water fountain. Active carbon and charcoal filters are made by design to trap many types of compounds.
Our active compound Oxygene is no exception and will stick to the filter, reducing the effectiveness of the water additive.
Filters that do not contain active carbon or charcoal may by used, however the pet water additive is most effective when drinking bowl and water are cleaned daily and refilled with fresh water and additive.