Top positive review
One person found this helpful
These definitely help with filtering out dirt & contaminants
on January 3, 2016
I purchased them to go with my PetSafe Drinkwell Original Pet Fountain. The definitely filter out dirt and contaminants because when I clean the fountain and change the filter I notice the white side of the filter has dirty spots on it -- these spots are the dirt and contaminants being caught. Before you put in a new filter be sure to thoroughly rinse out the filter so that any charcoal residue is completely rinsed out. Otherwise you will notice black residue in the bottom of the fountain, ie. in your cat's drinking water. I do use the filters longer than recommended and when I clean the fountain I will rinse the filter out and can usually rinse out the dirty spots that appear on the white side by using my hose from kitchen sink, so I am able to prolong the useful life of these filters.