Can Cats Drink Aquarium Water?

Some fish species thrive in aquarium water, so it’s essential to make sure the tank is full of beautiful, clean water.

This is why some people recommend adding cracked-open cat shampoo to the tank. Since the cat shampoo is a bit stronger than aquarium water, it can quickly affect them if left untreated.

So, can cats drink aquarium water? Cats can’t drink aquarium water because the pH level is too high for felines.

The pH level measures the relative acidity or alkalinity of a solution on a scale of 0 to 14, with 7 being neutral. The pH of aquarium water is between 7 and 8, while cats prefer a pH of 5.5 to 6.5.

Although cats do occasionally drink water with slightly acidic levels (around 6), they can develop serious health problems if exposed to an alkaline pH for more than a few days.

Can Cats Drink Aquarium Water?

Cats should not drink aquarium water It’s best to prevent your cat from having access to your fish tank water at all.

People who have fish tanks and cats in their house might think it’s a good idea to pour some aquarium water into the cat’s bowl or to water plants with water from the fish tank.

While this is a typical occurrence, cats should never be allowed to drink aquarium water.

When cats are thirsty, they like drinking water from a bowl or bottle – not water from a tank where they eat.

Many people say this is because cats are fascinated by the sight of fish swimming in tanks; they can’t get enough of it.

Many cat owners report that their cats refuse to eat or eat very little food if they’ve been drinking from the fish tank.

Because cats cannot be confined, they sometimes find other ways to access aquarium water.

Is Aquarium Water Toxic To Cats?

Aquarium water includes a lot of chemicals that can harm the health of both fish and cats.

Maintaining a fish tank, particularly one with live plants, requires a lot of maintenance, which can be difficult if you have other pets in the house or small children who often play around the tank.

Water quality varys from one fish tank to another: fish that live in the same tank might not necessarily have the same quality of water, even at the same temperature.

A cat may get unwell if his immune system is weakened by the chemicals present in aquarium water.

The nitrogen cycle in aquariums is a gradual process that involves the biological breakdown of fish waste.

The fish waste is expelled as ammonia which kills the fish inside and must be removed to another container which is full of bacteria which convert ammonia into nitrite and nitrate.

The nitrogen cycle in aquariums is a gradual process which involves the biological breakdown of fish waste.

Nitrite (NO2) is created when ammonia in the aquarium reacts with a bacteria called Nitrosomonas.

Nitrate has little effect on aquatic animals but nitrite is highly toxic and is converted into nitrate in the aquarium by Nitrobacter bacteria.

Cats that consume nitrate-laced water can suffer from a potentially fatal disease known as Nitrate Poisoning.

After the second or }th day the pet owner may start noticing reduced appetite and appetite loss as the pet is unable to absorb the nutrients in the food.

Cats inhale nitrates when they drink water and excrete them when the urine turns brown and smelly.

A fish tank’s water is not only dirty, but it may also contain toxic chemicals such as ammonia and nitrates.

Is It Harmful for Cats to Drink Water From a Fish Bowl?

Drinking fish bowl water is harmful to cats because enormous amounts of fish waste and algae builds up in the bowl.

As you can see, the pH level of aquarium water is quite high (6.5 to 8) and it’s too high for cats. Indeed, the pH level of aquarium fish water is much higher than the pH level of freshwater from lakes or streams (which is usually around 5).

Do Cats Like Fish Tanks?

Cats like fish tanks because they can see the fish swimming inside the glass tank, which they find fascinating.

Because of this, cats often find themselves licking the tank and the water in the fish tank. They also like to keep themselves wet by licking the tank’s glass walls.

Moreover, cats are naturally attracted to water and love to play with it; this is why they’re often found drinking from a puddle or pool outside your house or in the garden.

However, if a cat likes going through your aquarium and playing with the fish, it doesn’t mean your cat likes the dirty water of the tank.

Is It Possible for My Cat to Get Ill After Drinking Fish Tank Water?

Yes, drinking fish tank water is extremely harmful to your cat and can cause many health problems.

Some fish species thrive in aquarium water, so it’s essential to make sure the tank is full of beautiful, clean water. This is why some people recommend adding cracked-open cat shampoo to the tank.

Since the cat shampoo is a bit stronger than aquarium water, it can quickly affect them if left untreated.

Why Can’t Cats Drink From A Fish Aquarium?

Cat Diseases Are Difficult to Recognize

One reason cats should not drink from a fish tank is because they’re sensitive to some types of fish parasites and bacteria; these can be dangerous to your feline if passed to them through drinking water.

This means that even if your cat has a healthy immune system, it can lead to a number of cat diseases if exposed to these pathogens.

Toxin levels in a cat’s body can rise very quickly, especially when they’re exposed to a pathogen; this is why it’s important to provide clean water to your pet as soon as you notice them drinking.

Skin Rashes Could Result From Exposure

Bacteria, ammonia, nitrates, and other toxins in the water can cause illnesses such as dermatitis in cats.

These chemicals may be less dangerous to your cat than others, such as Giardia lamblia, but you should never underestimate their effects.

When cats drink from aquariums, they’re most likely to get infected or experience a skin rash as a result of exposure.

Algae growth, ammonia levels, and nitrates are principal causes of this skin disease.

Because cats are already susceptible to a variety of skin diseases, it’s wise to give them a break from your fish tank.

Furthermore, if a cat climbs on top of the aquarium and attempts to remove algae from it, they may accidentally ingest some of the plant matter or receive a skin rash from doing so.

Dangerous Uneaten Fish Food

Large quantities of uneaten fish food are another potential problem caused by aquarium water exposure in cats.

The uneaten fish food makes the water more acidic, which can weaken your cat’s immune system.

Cats that drink such water may suffer major health problems as a result, such as: diarrhea, vomiting, dehydration and even death.

Furthermore, uneaten fish food emits toxic gases that contribute to the amount of ammonia and nitrates in the water.

The degradation of fish food consumes oxygen in the water, which lowers the level of oxygen that the fish need to thrive.

The process also produces hydrogen sulfide (H2S) and the highly toxic substance methylmercury.

Because uneaten fish food particles block the gills of fish, it’s more likely to hurt the fishes and cause them to die.

Carbonates and Bicarbonates

Until it is cleansed, aquarium water contains dissolved solids that can harm a cat.

Meanwhile, drinking that water might contribute to the development of kidney disorders or bladder stones in cats.

Carbonates and bicarbonates are not dangerous to human beings, but they are deadly to cats.

General Difficulty

The quantity of calcium, magnesium, and sodium in the aquarium water can also affect the amount of water that the cat can drink without difficulty.

Aquarium water is often hard because it includes aquatic plants (like algae), inorganic salts and rocks that build hardness.

If your cat is exposed to hard water for a long time, it may develop metabolic acidosis.

PH Level

As the biological and chemical processes within the aquarium impact the pH of the water, this can have an adverse outcome on your cat’s health.

If the pH is too low or too high, it can harm the cat’s digestive system and impair its immune system.

If the pH of aquarium water is within the range of 6 to 8, it’s generally considered safe for cat to drink.

Because of the decomposition of organic waste within the tank and the water changes made to clean the tank, PH levels can change quickly within the water of the aquarium.

This indicates that the pH of aquarium water remains stable within a certain range.

Toxins Are Present in Fish Tank Water.

Aquarium water has a high concentration ammonia and nitrite which are toxic to cats.

Maintaining a fish tank is a difficult job that requires great monitoring of the parameters in the water of the fish tank.

Water quality varies on a daily basis but it’s not uncommon to see changes as much as 20T of aquarium water per week.

A cat may get ill from eating fish or bird food which the aquarium owner may unknowingly provide but the fish in the tank wouldn’t affect the cat.

How to Prevent Your Cat From Drinking Fish Tank Water

Teach Your Cat to Drink From Its Water Bowl.

Training a cat may be inconvenient but it’s the best way of preventing the cat from drinking from the fish tank water.

Give your cat a reward every time it uses its water bowl, be it a biscuit or a treat from its toys so that it can associate the fish tank water with negative things instead.

Place Your Cat’s Water Bowl on a High Place

Elevating or concealing our cat’s water dish may help us prevent it from drinking too much from the fish tank water.

When an animal is drinking water in the wild, it normally does so from water sources which are higher than the animal’s head level so if we place it on a high enough place, it may discourage the cat from consuming too much water from the fish tank.

Check That the Cat’s Water Bowl Is Clean.

If you use a plastic water bowl, clean it regularly and discard it if it becomes damaged because it might be contaminated by fish waste and can cause the cat to get sick.

This accumulation is one of the causes of cat illness.

Create a Routine.

Cats are known to stick to a schedule especially if they are well-trained.

This is why you should start them drinking from a bowl at a very young age so they will get used to drinking from a bowl and won’t opt for water from the fish tank.

Separate the Cat’s Food and Water Bowls.

Cats tend to keep their water apart from their food, thus separating the two bowls may help them to maintain a healthy routine.

Provide Your Cat with Fresh Water Regularly.

While we’re busy, we often forget to offer our pet with fresh water and they might resort to drinking from sources other than the water bowl, such as fish tanks.

It’s a good idea to keep a clean bowl of fresh water beside their bowl so that they can drink directly from it or from a natural water source like a pond or stream nearby rather than from the fish tank.

Protect the Fish Tank

Cover the fish tank with a mesh material to prevent the cat from consuming too much water from the fish tank and contaminating the fish with cat saliva and dander.

You just need to do this at night because they might miss out on feeding time since they will be occupied with drinking from underneath the mesh instead.

Keep the Fish Tank Safe.

This entails constructing a very thick glass cover for the fish tank to prevent any cats from jumping in and drowning themselves as well as from eating fish food with fish parts in it.

Get a Cat Water Fountain

Yes, there are water fountains created expressly for cats, but if you have a ceramic or porcelain water fountain, you can use it for your cat by filling it with clean water and placing ice cubes in the water to keep it cool.

Purchase a Larger Fish Tank or Dish

Your cat will enjoy it if you offer it with a larger tank or dish because the water will be fresher and will not have particles from uneaten food in it.

A larger tank or dish will also make it easy for your cat to drink clean water and stay hydrated.

Moreover, the larger size will make it less easy for your cat to access uneaten food, which will increase its chance of staying healthy in the long run.

Also Read: Can Cats Drink Tuna Water?


To summarize, it is typically safe for your fish to be fed dead fish or a live variety that contains natural bacteria because fish are carnivores and can survive on protein.

Never allow your cat to drink from a medicated fish tank because cats can easily become poisoned or die from consuming medicines that were meant to be used for the tank rather than the cats.

Protect your fish by covering the aquarium with a screen or grate so they cannot jump out and can not eat the cats.

Make it tough for your cat to approach the tank, but don’t make it too difficult for him to drink.

Finally, make sure you’ve done all possible to make your cat’s food healthy and nutritious and that he has plenty of water to drink.