DESC: Charcoal filter removes contaminants from your pets drinking water. The charcoal filter removes ordors to give your pet fresher drinking water. The easy to change filter should be replaced every 60 to 90 days. The three pack will give you six to nine months of water filtration. The filter reduces bacteria in your pet drinking water. Charcoal filter removes contaminants from your pets drinking water. The charcoal filter removes ordors to give your pet fresher drinking water. The easy to change filter should be replaced every 60 to 90 days. The three pack will give you six to nine months of water filtration. The filter reduces bacteria in your pet drinking water.