The Dirty Truth. How Often Should You Change Your Cat’s Water Fountain?


Keeping a cat’s water fountain clean and changing the water regularly is crucial for your cat’s health. Cats are notoriously bad drinkers, and a water fountain can help encourage them to drink more by providing cool, running water. However, stagnant water in a fountain can harbor bacteria, fungi, and algae that can make your cat sick. Changing the fountain water removes these contaminants and provides your cat with a fresh, appealing source of hydration.

According to veterinarians, staying hydrated supports kidney function, digestion, joint health, and more in cats. Dehydration increases the risk of urinary tract infections and kidney or bladder stones. By frequently changing your cat’s fountain water, you remove impurities and keep the water tasting fresh, promoting regular drinking. This ensures your cat is properly hydrated, allowing its body to function optimally.

Recommended Frequency

According to veterinary experts, cat fountain water should be changed at least once per week. More frequent changes may be required depending on factors like water intake and fountain capacity.

Veterinarians typically recommend changing a cat fountain’s water every 3-7 days. Most vets advise changing the water at least weekly as a minimum. Here are some general guidelines from veterinarians on frequency:

  • Daily – Change water daily for maximum freshness. This may be recommended for cats who drink more water or smaller fountain capacities.
  • Every 2-3 days – Change water every 2-3 days for cats with average water intake.
  • Weekly – Change water once per week at a minimum, even for cats who drink less. This is the bare minimum recommendation.

While daily changes provide the freshest water, changing at least weekly helps prevent buildup of biofilms, bacteria, and particulates that can accumulate over time. More frequent changes may be advisable depending on your cat’s needs and fountain capacity.

Factors Affecting Frequency

Several factors impact the frequency of when you should change the water in your cat’s fountain including:

The number of cats using the fountain is one of the biggest factors. The more cats using the fountain, the dirtier the water and the more quickly bacteria will build up. For a single cat household, you may be able to go 4-7 days between full water changes. In a multi-cat household (2 or more cats), water should be changed at least every 2-3 days.

Filter type is another important factor. Some fountains have charcoal filters which can help remove odors and particles before they re-enter the water source. This helps extend how long the water stays fresh. Fountains without a filter or simple foam/mesh filters will require more frequent changes.

Fountain capacity or size is also a consideration. Large capacity fountains over 1 gallon will need less frequent changes than smaller fountains under 1 gallon size. With a larger water volume, it takes longer for contaminants to reach problematic levels.

By considering these key factors – number of cats, filter type, and fountain capacity – you can gauge the ideal frequency to change the water for your cat’s specific needs.

Signs It’s Time to Change

There are a few telltale signs that indicate it’s time to change the water in your cat’s fountain according to experts.

Cloudy or murky water is one of the most obvious signs. As your cat drinks from the fountain, debris from their mouth can contaminate the water. Additionally, dust and minerals from the tap water can cloud the water over time (

You’ll also want to watch out for any debris accumulation at the bottom of the fountain. Things like hair and food particles can collect in the fountain and should be cleaned out during water changes.

The growth of algae or biofilms is another indicator. Algae and slimy buildup on the fountain walls means it’s definitely time for fresh water (

Finally, if the water develops a foul, musty odor, that’s a sure sign the water needs changing. Stagnant water allows bacteria to multiply, resulting in bad smells.

Cleaning the Fountain

Regularly cleaning your cat’s water fountain is crucial to provide fresh, clean drinking water. The fountain’s manufacturer will provide specific instructions, but there are some general guidelines to follow.

First, take the fountain apart and remove all of the components. Wash each part thoroughly with hot, soapy water. For mineral deposits or buildup, soak the parts in a 50/50 mixture of vinegar and water for 15-30 minutes before scrubbing clean (1).

The filter is one of the most important parts to clean or replace frequently. A dirty filter allows slime and bacteria to accumulate. Replace fountain filters every 2-4 weeks depending on usage. Some filters are reusable while others are disposable (2).

Make sure to fully rinse away any soap or vinegar residue before reassembling the fountain. Wipe down the cord and outside surfaces with a cloth and disinfectant. Let all parts dry completely before adding fresh water and turning the fountain back on.

Water Type

There are a few common options when it comes to the type of water to use in a cat fountain, including tap water, filtered water, spring water, and distilled water. Here are some of the key pros and cons to consider for each:

Tap water – Tap water often contains minerals that can build up in your cat’s water fountain over time. However, it’s readily available and inexpensive. Using a water conditioner can help remove chlorine and heavy metals (source).

Filtered water – Running tap water through a filter removes many impurities and minerals that can cause buildup in the fountain. It also improves taste. However, filters need regular replacement (source).

Spring water – Spring water is naturally filtered and contains beneficial minerals. However, it can be more expensive than tap water and still contains some impurities.

Distilled water – The distillation process removes nearly all impurities from the water. However, this also strips out minerals that may be beneficial for cats. Prolonged use of distilled water is not recommended.

In general, filtered tap water represents a good balance, removing many impurities while retaining some beneficial minerals. Tap water with a conditioner is also a good option. Avoid distilled water for daily use.

Fountain Location

When choosing where to place your cat’s water fountain, there are a few important factors to consider for your cat’s health and happiness:

First, locate the fountain away from your cat’s food bowls. Cats prefer having their food and water sources separated, so placing them in different rooms is ideal. Keeping them apart helps prevent the water from getting contaminated by food particles. According to veterinarians, cats should have access to fresh, clean water sources away from their food bowls (

Next, choose an easily accessible spot for your cat. Cats want quick access to water when they feel thirsty, so pick a location they can easily get to. Good places are countertops, corners of quiet rooms, or bathrooms. Make sure the fountain is not blocked by furniture or in high-traffic areas (

Also avoid placing the fountain in direct sunlight or near heat sources. Cats prefer cooler water temperatures, so prevent the water from getting too warm. Excessive heat can promote bacterial growth in the fountain as well (

Cat Behavior

Cats can be particular when it comes to drinking water, so transitioning to a fountain can take some adjustment. Be patient and try these tips to encourage drinking:

  • Place the fountain near your cat’s food bowls during mealtimes so they associate it with eating.
  • Consider getting a fountain with a lower water flow to start, as this may seem less intimidating.
  • Try putting a few treats or pieces of kibble floating in the fountain to spark curiosity.
  • Dip your finger in the fountain water and let your cat lick it off so they taste the water.

If your cat is hesitant to drink from the fountain after a few days, here are some troubleshooting ideas:

  • Make sure the fountain is clean and the filters are changed regularly, as cats dislike dirty water.
  • Try different water flow settings to find one your cat likes.
  • Consider switching to a different shaped fountain bowl.
  • Try placing the fountain in a different, quieter location.
  • Be sure your cat always has access to a regular water bowl as well until they transition.

With patience and experimenting with different techniques, most cats can adapt to using a fountain. But ultimately follow your cat’s preferences, and don’t force the issue if they refuse to drink from it.

Additional Tips

To keep your cat’s fountain clean and safe for your cat to drink from, follow these additional tips:

Once every month, deep clean the fountain thoroughly to remove biofilm and residue. Take everything apart, scrub with vinegar and rinse. This helps prevent buildup and bacteria growth.

Always top off the fountain daily so it stays full. Cats prefer fresh, flowing water. Letting the water level drop encourages bacteria growth on surfaces exposed to air.

Rinse the fountain bowl every day to prevent residue accumulating. Use a soft cloth and plain water to wipe away any dust or particles.

Following these simple tips will keep your cat’s fountain cleaner for longer between deep cleans, ensuring fresh appealing water.


In summary, the frequency with which you should change the water in your cat’s fountain depends on several factors. These include the number of cats using it, the cleanliness of your home, the type of fountain, and the quality of water going into it. While recommendations vary, a good rule of thumb is to empty and thoroughly clean the fountain every 2-7 days to prevent bacteria growth and odor. More frequent water changes and cleanings may be needed for multiple cat homes, ceramic rather than stainless steel fountains, or if you notice cloudiness, film, or odor. Cats who don’t seem interested in drinking from their fountain can also signal it’s time for a refresh. Changing your cat’s fountain water regularly helps ensure they have a good source of fresh, appealing water to support their health and hydration. Proper fountain maintenance keeps cats happily drinking and decreases issues like UTIs or bladder stones.

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