Can You Use Tap Water in Your Cat’s Water Fountain? The Answer May Surprise You


Cat water fountains have become increasingly popular in recent years. Unlike stagnant water bowls, fountains provide fresh circulating water, which encourages cats to drink more. Proper hydration is crucial for cats’ health, as it helps flush their systems, prevents urinary tract infections, and supports kidney function. However, some cat owners worry about using tap water in fountains due to potential contaminants.

While tap water is treated for human consumption, debate exists over its suitability for pets. Some claim contaminants like chlorine or fluoride may be harmful, especially as cats tend to drink less water than people. Hard water can also leave mineral deposits behind. Cat fountains offer filtration, but questions remain over their ability to purify tap water. This article will explore the safety of tap water for cat fountains and examine options for filtration.

Tap Water Safety for Cats

In general, tap water is safe for cats to drink in most areas. Tap water in the United States is regulated by the EPA for safety and must meet standards for contaminants (1). However, there are some considerations when it comes to cats drinking tap water.

One concern with tap water is the chlorine used to disinfect it, which can alter the taste. According to veterinarians, the amount of chlorine in tap water is very minimal and not harmful to cats (2). Some cats may dislike the taste of chlorine in the water.

Another component in tap water is fluoride, which is added to prevent tooth decay. While small amounts of fluoride are not toxic to cats, higher concentrations can cause health issues if ingested over time. Monitoring your tap water fluoride levels can ensure it stays within a safe range (3).

Hard water with high mineral content is another factor with tap water. This may lead to urinary tract issues in cats over time when they consume it regularly. Using a water softening system or filter can help reduce the mineral content (4).

Overall, standard tap water that meets EPA regulations is generally safe for feline consumption. But filtering tap water, using bottled water, or providing a cat fountain can improve taste and remove any impurities cats may be sensitive to.



Filtration Ability of Cat Fountains

Cat fountains filter tap water through different types of filtration systems to remove impurities and improve taste. According to The Spruce Pets, most cat fountains use a carbon filter to remove chlorine and other chemicals from tap water[1]. Carbon filtration improves the smell and taste of water, making it more appealing for cats to drink.

Some more advanced cat fountain models, like the PetSafe Drinkwell Platinum fountain, utilize a combination of carbon filtration and ion-exchange resin to filter out chemicals and soften hard water. As reported by The New York Times, softening the water this way makes it taste better to cats[2]. Models with multiple filtration stages tend to be more expensive but can filter water more thoroughly.

The frequency that filters need to be changed depends on the model. Most carbon filters last 1-2 months before needing replacement. Ion-exchange filters may last a bit longer. Replacing filters regularly is important to maintain filtration and water freshness.

Removing Chlorine

Tap water contains chlorine, which is added by water treatment facilities to disinfect the water supply. However, chlorine can be harmful to cats if ingested in large quantities over time. There are a few options for removing chlorine from tap water before using it in a cat fountain:

Letting water sit – Allowing tap water to sit uncovered for 24-48 hours before use allows the chlorine to dissipate into the air naturally. The chlorine will off-gas during this time.[1]

Using a dechlorinating product – There are chemical dechlorinators made specifically for pets that neutralize chlorine. They come in liquid or tablet form and are added to the water. Popular brand names include Tetra AquaSafe and API Tap Water Conditioner.[2]

Activated carbon filtration – An activated carbon water filter attached to the cat fountain will remove chlorine effectively. The carbon absorbs chemical contaminants as the water passes through. Filters need to be replaced per the manufacturer’s recommendation.

Reverse osmosis filtration – A reverse osmosis system can be installed to remove chlorine and other contaminants from tap water prior to use in the cat fountain. This option requires more investment and ongoing filter changes.

Removing Fluoride

Fluoride can be concerning for cats when ingested in high quantities. While small amounts are not immediately dangerous, buildup over time from drinking tap water can lead to fluorosis and bone issues.

To remove fluoride from tap water before using it in a cat fountain, there are several effective filtration methods:

Reverse osmosis systems force water through a semipermeable membrane, filtering out contaminants like fluoride. According to this source, reverse osmosis removes up to 93% of fluoride.

Activated alumina filters contain aluminum oxide that bonds with fluoride ions, capturing them in the filter. Fluoride molecules have a strong affinity for binding to the alumina.

Distillation involves boiling water and condensing the steam, leaving behind contaminants like fluoride. The distilled water produced is essentially pure H2O.

For cat owners concerned about fluoridated tap water, using filtered or bottled spring water in the cat fountain is an alternative. This avoids exposing cats to higher levels of fluoride altogether.

Softening Hard Water

Hard water contains high levels of minerals like calcium and magnesium. While these minerals are not harmful to cats in small amounts, excess minerals from hard water can lead to potential health issues for cats over time.

One study found that the minerals in hard water may contribute to bladder stones or crystals forming in cats. The minerals make the urine more alkaline, allowing crystals to develop and clump together in the bladder. This can lead to blockages and pain during urination.

Water softeners can help reduce the mineral content in hard water by using a process called ion exchange. The ion exchange system replaces the calcium and magnesium ions in hard water with sodium ions. This makes the water feel “soft” and lather better without affecting the water’s safety.

According to pet experts, softened water is generally safe for pets to drink. The sodium content is low enough that it does not cause problems for healthy pets. However, cats with kidney disease or heart conditions may need to avoid softened water, so check with your vet.

Reverse osmosis systems are another option for removing minerals from hard water. These systems use a multi-step filtration process with a semipermeable membrane to eliminate minerals. The resulting water has very low mineral content. However, reverse osmosis water may be too pure and should be remineralized before giving to pets.


Keeping a cat water fountain clean is important for providing cats with safe, fresh drinking water. Cat fountains contain filters that need to be changed regularly to remove contaminants and keep water fresh. According to KittySpout, filters should be changed about every 2-4 weeks depending on usage and water conditions (source). The fountain bowls, pumps, tubes, and other parts that come into contact with water also need regular cleaning to prevent the buildup of slime, bacteria, and mold.

Most cat fountain manufacturers recommend a thorough cleaning about every 2-4 weeks. This involves disassembling the fountain, cleaning all parts with hot soapy water or in the dishwasher, and replacing the filter. In between thorough cleanings, wiping down surfaces and changing water frequently helps keep fountains clean for cats. By properly maintaining a cat water fountain according to the manufacturer’s instructions, cat owners can ensure the fountain provides a healthy water source.

Bottled or Filtered Water

When it comes to using bottled or filtered water in cat fountains, there are some pros and cons to consider:

Pros of bottled/filtered water:

  • Removes contaminants like chlorine and fluoride commonly found in tap water (CatHealth)
  • Provides clean, fresh tasting water that may encourage drinking
  • Convenient option if tap water quality is poor

Cons of bottled/filtered water:

  • More expensive than tap water
  • Bottles create plastic waste
  • Still need to clean fountain regularly as stagnant water can develop biofilm
  • May be unnecessary if tap water is good quality

In areas with poor tap water quality, the benefits of bottled or filtered water likely outweigh the extra cost. But for most households, regular tap water changed daily is sufficient for cat fountains. While bottled water is an option, tap water run through a filter or fountain’s built-in filter removes unwanted contaminants at a lower cost and waste.


When it comes to using tap water in cat fountains, there are a few key considerations. The safety of tap water can vary greatly by location, with factors like chlorine, fluoride, and mineral content needing to be addressed. Many cat fountains have built-in filtration systems that can remove some impurities, but not all models are created equal. Activated carbon filters are best for eliminating chemicals like chlorine, while mineral filters can reduce hardness and soften water. However, filters require frequent replacement and maintenance is critical. Some pet owners opt to use bottled or filtered water instead of tap water to avoid potential risks. Ultimately, it’s important to understand your local tap water quality, research filtration abilities of different fountains, and take steps to provide fresh, contaminant-free water for cats. The ideal cat fountain setup balances convenience and safety.


Based on the information provided, using tap water in cat fountains can be safe and effective as long as the tap water is properly filtered. Cat fountains with multi-stage filtration systems using carbon and ion exchange filters are capable of removing potentially harmful contaminants like chlorine, fluoride, and heavy metals.

To ensure the ongoing safety of tap water for cat fountains, be sure to follow the manufacturer’s instructions for cleaning and replacing filters. Testing your tap water periodically is also a good idea. If water quality is a major concern or you have especially hard water, using bottled or pre-filtered water is recommended.

Providing fresh, flowing filtered water encourages cats to drink more, promoting urinary tract health. Cat fountains with filtration allow owners to conveniently give cats water from the tap without compromising quality and safety.

For readers considering a cat fountain for the first time, models certified by the Veterinary Oral Health Council that offer multi-stage filtration are highly recommended. Be sure to clean and maintain the fountain according to instructions. To give your cat the best possible drinking experience, invest in a fountain with superior filtration.

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