How Often to Change a Cat Fountain Filter

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Quick answer

PetSafe says to replace a Drinkwell carbon filter every 2 to 4 weeks and the foam filter every 1 to 2 months. Catit says to replace its Flower and PIXI pads every 30 days. Cleaning is on a separate schedule, and both makers say it matters as much as the filter.

Replacement filters:

Catit Flower Filters (#43745) Catit PIXI Filters (#43721) PetSafe Carbon (PAC00-13906) PetSafe Foam (PAC00-13711)

The makers' schedules side by side

Cleaning and filter intervals as PetSafe and Catit give them.

Task	PetSafe Drinkwell (½, 1, 2 gallon)	Catit Flower / PIXI
Wash the fountain	At least once a month; multi-pet homes may need it more often	Weekly, per the Flower LED manual
Rinse the filter	Rinse a new carbon filter under cold water (30 seconds, per the slimy-fountain guide)	Rinse it at the weekly wash; don't wash it with soap
Replace the carbon filter or pad	Every 2 to 4 weeks	Every 30 days (product pages); 3 to 4 weeks, or sooner if saturated or the flow slows (manual)
Replace the foam filter	Every 1 to 2 months	No separate foam; the pad has a cotton mesh layer
Clean the pump	Each time you take the fountain apart to clean it	Every two weeks (cleaning guide); the manual says open it whenever it looks dirty

Catit's manual adds that more frequent filter changes may be needed with several pets, or because of your home's water and conditions.

If the fountain is slimy

PetSafe's fix for a slimy Drinkwell is a full clean, not just a new filter:

Take the fountain apart and take the pump apart.
Soak all the fountain and pump parts in equal parts vinegar and warm water for up to 20 minutes.
Scrub everything with soap and warm water, including crevices, corners and inside the pump where the impeller sits.
Rinse all parts well so no soap or vinegar is left.
Put the pump back together, fit a new carbon filter (rinsed under cold water for 30 seconds) and reassemble.

PetSafe says the plastic fountain parts can go in the top rack of the dishwasher, but not the pump, power adapter or filters. Catit says to wash all components with warm water, a soft sponge and dish soap, and never use aggressive detergents or an abrasive sponge. Catit also says to clean the top parts regularly to prevent scale.

Soap and filters: Catit's manual says not to wash the filter with soap. PetSafe says not to use bleach or other harsh chemicals on the pump.

How much should a cat drink?

The Cornell Feline Health Center puts it at about 4 ounces of water per 5 pounds of lean body weight per day, so about a cup for a 10 pound cat, and notes wet food can be up to 80% water. Cornell says some cats drink more when given a fountain, but cats' preferences vary. If you're worried your cat isn't drinking enough, Cornell's advice is to contact your vet.

Not sure which pack fits? See the PetSafe vs Catit vs Veken filter guide.

How we work: intervals and cleaning steps come from PetSafe support articles, Catit product pages, the Catit Flower Fountain LED manual and Catit's cleaning guide. Water guidance comes from Cornell. All are listed below. We have not tested these fountains.

Questions people ask

How often should I replace my cat water fountain filter?

PetSafe says Drinkwell carbon filters every 2 to 4 weeks and foam filters every 1 to 2 months. Catit says its Flower and PIXI pads every 30 days; the Flower LED manual says every 3 to 4 weeks, or sooner if the filter looks saturated or the flow slows.

Why is my cat fountain slimy even with a fresh filter?

A new filter doesn't clean the bowl. PetSafe's fix for a slimy Drinkwell is to take the fountain and pump apart, soak the parts in equal parts vinegar and warm water for up to 20 minutes, scrub with soap and warm water, and rinse well. PetSafe says to clean the fountain at least once a month, more often with several pets.

How often should I clean a Catit fountain?

Catit's Flower LED manual gives weekly maintenance: wash the fountain with a soft sponge and non-abrasive cleanser, rinse well, and rinse the filter without soap. Catit's cleaning guide says to take the pump apart and clean it every two weeks.

Sources

Last checked Oct 23, 2026. Fountain tray shapes and pump models change by revision; check the maker's part number on your fountain base or manual before ordering.

How often to change a cat water fountain filter (and clean the fountain)