Cat Fountain Filter Direction. If the pol filter is not correctly rotated for the direction you are shooting in, it either wont have any effect at all (besides as a general nd filter) or you will see the effect only in half the picture which looks really ugly. Fill the bowl with water to the fill line.

The small quantities of activated carbon that escape from the filter will not harm your cat. The charcoal filter may be rinsed out when the fountain is cleaned. Keep the water level close to the fill line at all times to prolong the life of the pump.