Review on Catit Design Replacement Filtering Cartridge by Whitney Buckley

I have two Hagen Catit fountains. An old light green version and I have a new teal blue one. I used the old filters in green until I got a newer version with those filters and the new filters do the job just fine. Much better than the old filters. I've often noticed coarse slime in the green fountain, and with these new filters it's almost gone. The new style filters go really well with the old style fountain (they are almost the same design). I probably change the filters every few months when I feel they really need to be changed, while also giving the wells a thorough cleaning. My two cats are definitely drinking more because of the fountains.