Is Tap Water Really Bad for Pet Rats?

Is Tap Water Really Bad for Pet Rats
Is Tap Water Really Bad for Pet Rats

Rats are fun animals to have as pets. There intelligent and affectionate little creatures keep themselves as clean as cats do and are incredibly easy to look after. But as a responsible owner, you are bound to come across some questions regarding pets. And information about pet rats is hard to come across online.

One question many owners seem to have is whether tap water is bad for their pet rats. Well, it depends on where you live. In many places, particularly in the U.S., the water is chlorinated and fluoridated. While the amount of fluoride/chlorine is okay for an adult human, it may not be so for a rat.

In this article, we will explore this topic further. Do you really need to give bottled water to your pet rats? What safety measures can you take? How toxic is that tap water for your rat? We will cover all of that here. We will also briefly discuss the drinking habits of pet rats. 


What is tap water & is it harmful to rats?

Tap water is the water that you get from your local water treatment facility. It is considered to be one of the privileges of living in the first world. Clean water that you can directly drink from the tap. That’s definitely something!

But how exactly is the tap water in your house cleaned? What exactly does the water treatment facility do?

Water from some natural source, usually a river or a nearby lake, is directed to a treatment facility. Here, the water gets treated with a bunch of chemicals, predominantly chlorine and fluoride. Chlorine helps remove most of the harmful bacteria and other infections naturally present in water, whereas adding fluoride to the water is supposed to help prevent your teeth from decaying. Once the water is treated, it is directed via pipelines into your homes, where you can access them via tap.

The amount of chlorine or fluoride present in the treated water you get from your tap is perfectly okay for an adult human to drink. But they are usually deemed harmful for infants and small pets, pet rats included.

The thing about fluorine/chlorine is that while they’re able to clean and treat large volumes of water for humans to consume, they can be poisonous for pet rats. Fluoride, in particular, is very harmful to rats. And the amount of fluoride and chlorine used to treat the water will vary from time to time and place to place. So even though a lot of pet rat owners have reported that they regularly give their rats tap water, it’s better to be safe than sorry.

What safety measures can you take?

So we’ve established that it is better if you just try and avoid giving tap water to your rat. So what can you do here?

Most homes already have a filtering system installed. Even though authorities in the U.S. are required by law to ensure that the water you get in your tap is drinkable, it’s always a good idea to have some sort of a filtering system installed. And if you have hesitated to install one so far, it is time you finally do it. For your furry little buddies, if not for you. 

One thing you need to be mindful of when getting a filtration system, make sure you get something like a Brita filter that promises to specifically remove fluoride and chlorine from the water. These are, after all, what you’re trying to get rid of.

If you don’t want to go ahead and invest in a water filter right away, there is another option for you.

Bottled water for your rats

A lot of pet rat owners opt to give their rats bottled water. You could invest in a filtration system or distill the water you get from your tap. But why bother when you can just get bottled water for so cheap. Most people have these lying around in the fridge anyway. 

Bottled water for rats may seem too ostentatious, but it’s a small price to pay for the health of your precious little pets. And it is quite literally a small price. Rats don’t drink a lot of water anyway, so you don’t have to worry about this being an expensive habit.

How much water does your rat need?

Your pet rats will need 24/7 access to water. But that doesn’t necessarily mean your rats will drink a gallon a day. Most adult rats need 10ml of water per 100gm of body weight per day under normal weather conditions. When it’s warmer, they may need up to 35ml (1.9 oz), but that’s about it.

Now let’s do a quick calculation. Given that an average rat weighs between 200 to 250 grams, your rat will drink between 20-25ml (0.7 oz-0.8 oz) of water on average per day. This means that a 500ml (or 16.9 oz) bottle of water should serve a pet rat for 20-25 days. So it makes bottled water an extremely cheap way to ensure your rat’s good health.

On a side note, Rats have quite a reputation for being able to survive without water. Some rats can survive up to 30 days without water. One way rats are able to achieve this is thanks to their indirect way of consuming water. Rats have a much higher capacity to derive water from dry fruits and other foodstuffs than we humans do.

Of course, you wouldn’t want to run an endurance test on your precious little rat baby. While they are resilient creatures, rats get stressed very easily. So make sure your rats have easy access to water. You can either use a bowl or a water bottle with a lever to give water to your rat. Water bowls are easy but can cause a lot of mess. 

Rats tend to flip the bowls over, thus spilling the water. Water bottles are cheap to get and easy to install. As long as you train your rat to use them a couple of times and change the water on a daily basis, you should be good.


Regular water is processed using chlorine and fluoride, among other chemicals, to give you the tap water that you get in your house. While tap water, by law, is required to be safe for direct consumption by humans, they aren’t necessarily safe for rats to drink.

Chlorine is used to kill the bacteria and other vermin infesting the natural sources of water. Fluoride is believed to help prevent tooth decay. While these two chemicals are pretty much harmless at trace amounts to humans, they can be deadly for rats. A lot of pet rat owners do claim that they give tap water to their rats. But you should know that the number of chemicals in tap water will vary from place to place and from time to time. This is why it’s always safe to avoid giving tap water to your rat.

As an alternative, you can either use filtered water (if you have a filtration system installed) or give you rat bottled water. If you’re using a filtration system, make sure it specifically treats chlorine and fluoride, as these are the chemicals you most need to remove. Bottled water, however, is a great alternative, since they are cheap and your rats don’t drink an awful lot of water anyway.