Leaving Water in Cat Fountain. How Long is Too Long?


Cat fountains provide a number of benefits for both cats and their owners. Unlike a regular water bowl, fountains circulate and filter the water, keeping it cooler and fresher for longer periods of time. The moving water that fountains produce is also more enticing to cats, as their natural instinct is to drink from streams and moving sources. This often results in increased water consumption, which is important for urinary tract health.

However, as with any water source, fountains can allow bacteria to accumulate if the water is not changed regularly. Stagnant fountain water allows biofilm to build up over time, which can spread illness if a cat drinks from a contaminated source. For this reason, it’s important to follow the manufacturer’s recommendations for changing and cleaning the fountain water on a consistent basis.

How Often Should You Change Cat Fountain Water

For the healthiest water, experts recommend changing your cat fountain water daily. Fresh water helps prevent the growth of bacteria, fungi, and other microorganisms that can make your cat sick. According to one source, “Clean the fountain every 3 to 4 days for multiple cats, every 5 to 6 days for a single cat.”

While some sources say the water only needs to be changed every 2-3 days, daily is ideal. The more time water sits, the more opportunity there is for contamination. Bacteria and biofilm start growing within 24 hours, so longer between changes increases the risk. Changing water daily provides the freshest, healthiest hydration for your cat.

Never leave the fountain water unchanged for longer than 3 days. Any longer than that allows dangerous bacteria like Salmonella or E. coli to flourish. Stagnant water also takes on an unpleasant odor and flavor that may dissuade your cat from drinking. For their safety and enjoyment, swap out the water daily.

Signs the Water Needs Changing

There are a few key signs that indicate it’s time to change the water in your cat’s fountain:

  • Cloudy, smelly, or discolored water – Clear and odorless water is ideal. If the water appears dirty, cloudy, or has a strong odor, it needs to be changed.
  • Buildup of food, hair, etc in fountain – Over time, debris from your cat’s drinking can accumulate. Excessive buildup indicates stagnant water.
  • Reduced water flow – If the fountain’s flow seems slower than normal, sediment buildup may be blocking the pump or filters.

According to Catit, discoloration like green, brown, or pink hues often comes from algae, biofilm, or bacteria accumulating over time. This is a sign stale water should be replaced.

Smelly water also hints that bacteria is growing inside the fountain. Bacteria can spread to your cat’s skin and mouth when drinking, causing conditions like acne or gingivitis. Foul odors mean it’s crucial to refresh the water.

Listening for reduced bubbling or flow is another simple check. If the fountain seems clogged or flows weakly, replacing the water can help clear the system.

Cleaning the Fountain

Thoroughly cleaning the fountain on a regular basis is essential to maintaining proper hygiene for your cat. It’s recommended to fully clean the fountain at least once a week. Here is a step-by-step process for cleaning the fountain:

1. Unplug the fountain and remove all parts – Take apart the fountain completely by removing the pump, filters, bowls, tubes, and lids. Place the pieces in the sink or a large container.

2. Clean with hot water – Rinse all parts with hot water to remove debris and built-up sediment. For tough stains, you can use a soft brush or cloth.

3. Wash with cat-safe cleaner – Mix a cat-safe, pet-friendly cleaner in hot water according to instructions. Vinegar or lemon juice can work well. Gently wash each piece with a soft sponge or cloth.

4. Rinse thoroughly – Double check that all soap residue is removed by rinsing under hot water. This prevents contamination or upset stomach if kitty drinks any cleaner.

5. Allow to fully dry – Place parts on a clean towel and allow to completely dry before reassembling. Do not plug in while still wet.

6. Reassemble – Once dry, reassemble the fountain by replacing all parts in their correct order and plug back in.

Repeat this cleaning process weekly or more often if you notice sediment build-up or film on the fountain. Proper cleaning is key to keeping fresh, appealing water for your cat.

Maintaining Proper Hygiene

Keeping your cat’s fountain clean between full water changes is crucial for maintaining proper hygiene. Here are some tips for keeping the fountain clean:

Wipe down all surfaces of the fountain daily with a soft cloth or sponge. Pay close attention to corners and crevices where bacteria can build up. According to petlibro.com, you can use a solution of one part white vinegar to two parts water to help remove mineral deposits and disinfect.

Every few days, take apart the fountain and clean the individual components. Scrub any built-up debris with a soft brush and rinse thoroughly. Allow all parts to air dry fully before reassembling.

Always wash your hands thoroughly with soap and warm water before handling your cat’s fountain. This helps prevent transferring bacteria from your hands into the water.

Avoid letting the fountain go more than a week without a thorough cleaning. The longer debris and minerals sit, the harder they will be to remove.

Following proper hygiene practices in between full water changes can help keep your cat’s fountain fresh and free of harmful bacteria buildup.

Water Type Considerations

When it comes to cat fountains, one of the most important factors to consider is the type of water used. There is some debate over whether filtered or unfiltered water is better for cats.

Many experts recommend using filtered water in cat fountains to remove contaminants like heavy metals, chlorine, and fluoride that can be harmful to cats over time. Filters help provide cleaner, better tasting water that cats will be more inclined to drink. According to the American Veterinary Medical Association, filtered water is ideal for promoting optimal feline health. The Thirsty Cat Fountain recommends filtered water to avoid scale buildup and keep the fountain operating properly.

However, some cat owners have success using unfiltered tap water. The key is making sure to regularly change the water before it becomes too unsanitary. Tap water may contain more minerals that can contribute to fountain clogs and stains over time. More frequent cleaning is required.

Many cats prefer running water, as instinct draws them to moving streams and fountains. The sound and motion of water flowing from a fountain encourages cats to drink. Cats tend to drink more from fountains than standing bowls, helping promote hydration. So providing filtered, running water in a fountain satisfies a cat’s natural drinking preferences.

Location Tips

When deciding where to place your cat’s water fountain, it’s important to choose a spot that will encourage drinking and promote proper hygiene.

Most experts recommend placing the fountain away from your cat’s food bowls. Keeping their food and water sources separate can help prevent cross-contamination and allow you to better monitor intake of both.

Avoid high-traffic areas of your home, as this can make some cats feel uneasy. The noise and activity may prevent them from approaching the fountain. Quiet spots like the bathroom or bedroom are often good choices.

Be sure to position the fountain so the power cord is out of reach and cannot be chewed on. Placing it behind furniture or up on a counter can help keep your cat safe.

Choosing a Fountain

When selecting a cat fountain, you’ll need to decide between plastic and ceramic models. Plastic fountains are typically more affordable and durable. However, ceramic fountains can be more attractive and often use dishwasher-safe parts for easy cleaning. According to the NY Times, plastic fountains like the Catit Flower Fountain tend to be top-rated for reliability and ease of cleaning.

You’ll also want to consider capacity based on your needs. Larger 3-5 liter fountains like the Petsafe Drinkwell Pagoda are ideal for multi-cat households. Smaller 1-2 liter models can suit single cat homes well. The Spruce Pets recommends opting for larger fountains if you have more than 2 cats so the water doesn’t need refilling as often.

Troubleshooting Issues

Some common issues that can arise with cat fountains include the pump not working properly, the fountain leaking, or the cat not drinking from the fountain. Here are some troubleshooting tips:

If the pump seems to not be working, first check that the power cord is plugged in and the outlet is functioning. Then check that the pump lever or switch is in the on position. Refer to the specific fountain’s instruction manual. You may need to disassemble the pump housing and clean the impeller if hard water deposits have built up. Use a small brush with warm soapy water to scrub the impeller, then rinse thoroughly. Refer to this guide for troubleshooting pump issues.

Check O-rings and tubing for cracks or damage which can cause leaking. Make sure all fountain parts are fitted together properly without gaps according to the instruction manual. Clean any mineral deposits around joints. Replace damaged or worn parts. Putting pet-safe silicone sealant on outer joints can help stop leaks.

If your cat is hesitant to drink from the fountain, try washing it thoroughly to remove any plastic smells. Make sure the water level is filled to capacity so the stream is inviting. Place the fountain in a quiet, low-traffic area. Consider getting a fountain with a flower or mountain design if your cat prefers running water. Moving the fountain closer to your cat’s food may encourage drinking. Refer to this guide for troubleshooting cat drinking issues.


Cats need access to fresh, clean water at all times for proper hydration and health. While there isn’t a definitive answer for how long water can sit in a cat fountain before needing to be changed, the general recommendation is to refresh the water daily. The signs that it’s time for new water include cloudiness, smell, debris accumulation, and bacterial buildup. To keep your cat drinking and thrive, be diligent about cleaning the fountain thoroughly each week and providing your feline friend with a consistent supply of fresh, appealing water.

By establishing a routine for fountain maintenance and water replacement, you can ensure your cat has healthy, hydrating water available at all times. The small effort of changing the water daily and cleaning the fountain weekly is well worth it for your cat’s wellbeing. Proper hydration supports urinary tract health, kidney function, digestion, and overall vitality. Your cat relies on you to meet this basic need. Be vigilant in providing fresh, clean water, and your cat will respond with better health and happiness.

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