The type of water you put in your betta fish’s tank can have a major impact on their health. Water might look the same, whether it comes from your faucet or from a bottle you buy at the store. But, just like the air we breathe, the water betta fish live in needs to be just right. We want to replicate their natural habitat and required nutrients. By following these water guidelines, your betta fish will be happy, healthy and beautiful.

Tap Water for Betta Fish?

Tap Water

The water most readily available for most of us is the water that comes straight from a faucet. Depending on where you live, tap water usually has added chemicals like chlorine. These chemicals make tap water safe for us to drink. Those same chemicals that help us are capable of hurting, or even killing, a betta fish.

Luckily, there are plenty of high quality, and inexpensive water conditioners to remove chemicals from your tap water in seconds. This makes it safe for your betta fish to live in. There are betta-specific water conditioners and one’s for freshwater fish in general, either are fine to use.

Tap water is excellent for betta fish because once you remove the chlorine, chloramines and other heavy metals, it contains a variety of nutrients and minerals betta fish need to thrive. It’s also very easy to mix hot and cold water together to make it the perfect temperature for your betta’s habitat (test with a thermometer).

Betta fish are happiest and healthiest when the water temperature is between 76 and 82 degrees Fahrenheit. In order to keep your water temperature within that range, you may need to purchase a heater for your betta fish if the surrounding room is colder.

Spring Water for Betta Fish (Bottled Water)?

Spring Water for Betta Fish

Bottled spring water is a more expensive alternative to tap water, but unlike distilled water, it hasn’t been processed to remove minerals and nutrients. This water will not have chlorine in it, either, so it is safe to use in betta tanks as long as the pH levels fall in line with safe betta levels.

Always make sure to check the pH of your water before adding it to your tank. Different brands of bottled water contain different pH levels due to their processing. Make sure you have pH up or down treatments available to alter the level if necessary.

Gallons of spring water can be purchased for a dollar or two at your local supermarket, and if the pH level is fine, it already contains the nutrients your fish will need to stay healthy. It can also be kept on hand in the same room as the tank, so the temperatures of the water in the bottle and the tank should be similar. A stress coat additive is also recommended when using spring water.

Distilled Water for Betta Fish?

Distilled Water for Betta Fish

Distilled or purified water, is very different from regular tap water because it has been processed to remove all chemicals, minerals, and nutrients, leaving you with nothing but pure water. While distilled water has many uses, it should not be used in betta habitats without proper treatment to add nutrients and control pH levels.

Betta fish living in untreated distilled water lack many of the minerals they need to survive, and as a result, will lack energy, have a dull looking appearance and could die. It does not make sense to use distilled water because of the required addition and measurement of nutrients and pH. Use tap water or bottled water instead. This kind of water for betta fish is not recommended.

Betta-Specific Water

Betta-Specific Water

You may also come across water that is labeled specifically for use with betta fish. This bottled water has been pre-conditioned for betta fish. It falls within the correct pH and has been stripped of harmful chemicals and metals. Using this water is not required since you can treat tap water on your own. It’s also a lot more expensive. The choice is yours, however, if you want the convenience of water that is ready to add to your tank immediately.

Well Water for Betta Fish?

Chances are, those who live in a rural area without access to city water, are using water that comes from a well. While you might think this water is safe because it hasn’t been treated with chemicals like municipal tap water, you’d be wrong.

Well water can contain chemicals used in pesticides and fertilizers or high quantities of heavy metals like copper or iron. Problems may also arise if you’re treating your water with chlorine to remove contaminants for drinking.

Most local pet stores will test your water if you bring in a sample. This is highly suggested if you’re unsure. Though many conditioners treat heavy metals, chlorine and other contaminants that could hurt your fish, there are options available to treat only heavy metals too. Always make sure the water’s pH levels are appropriate for your betta fish too, something a test will tell you.

Betta Fish & Water pH Levels

It’s important to keep pH in mind when establishing a new tank or changing out the water. Betta fish prefer a pH between 6.5 and 8 but can tolerate slightly more acidic water if the change is made gradually. For the most part, water will maintain a pH near 7, which is considered neutral.

For bottled spring water, pH levels can range anywhere from below 6 to higher than 9. No water is ever going to be a perfect 7. Oxidation occurs the second it’s exposed to the open air. To make sure your betta fish is in the highest quality water possible, perform a pH test on your tank’s water BEFORE adding him or her to the tank. Test strips are inexpensive and can save your betta’s life.

As your betta fish poops in the tank and as uneaten food and debris collect, the pH will increase. This is why water changes and cleanings are so important. The smaller the tank, the faster the water’s parameters can fluctuate.

Changing Your Betta Fish’s Water

Always limit drastic changes in temperature and pH. Betta fish need to get used to the new water in their tank. Cycling (changing a portion of the water) and acclimation can really help. These reduce stress which is very dangerous to a betta fish’s health.

Cycle 20-40% of the water in their tank at evenly spaced intervals. This will depend on the size of your tank, and whether or not it is filtered. Full water changes are also needed weekly

For example, a 2.5 gallon unfiltered tank involves cycling 20% once or twice a week with new, properly treated water and a full 100% water change every 7 days. This keeps the water as consistent as possible; lessening the amount of ammonia, bacteria, and stress on your betta fish.

What to Remember

The most important lesson to remember is that not all water is created equal. Water quality varies greatly depending on the source. Water parameters should be taken into consideration when establishing or renewing water in your betta’s tank. Tap water or spring water are the best kinds of water for your betta fish. Keep water test strips available to easy testing.

You can also add aquarium salt to your betta’s water to help protect your fish from common parasites and fungi. Always dissolve and treat it in a separate container before adding it to your betta fish’s tank.
The addition of aquarium salt also reduces stress and swelling, aids in a healthy slime coat, and promotes healthy fin growth. Furthermore, it recreates the salinity in their natural habitat and can prevent harmful nitrate intake.

Did you find this information helpful? Still, have questions about what kind of water to use for your betta fish? Let us know in the comments below.

About The Author

Founder & CFO (Chief Fish Officer)

Founder of and betta fish enthusiast. With over six years of betta husbandry experience, I wanted to create a place that was educational and fun for other betta keepers. Stick around, you'll learn a lot!

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18 Responses

  1. Sylvia

    I have a 10 gal tank. I have 2 boy guppies and 2 snails for about a month. I finally put in a beautiful baby boy betta. He has more than doubled in size in a month. Everyone is getting along. The guppies be trying to bother the betta. The betta act as if he don’t see them. I use to feed 3 times a day. Now i feed twice a day. Do you think that the betta will kill the guppies as he gets bigger. Or the guppies able to kill the betta. I just hope the mansion i gave the betta will be well worth it. How big will my betta get in a 10 gal tank?

    • Bryan

      That’s great to hear Sylvia, if they are feeder guppies you will have a better chance than fancy guppies because of bright coloring. It’s hard to say because all temperaments are different, you’ll have to keep an eye on them and leave plenty of hiding spaces. Your betta will get to be around 2-2.5 inches in length (body), unlike goldfish for example, they do not get bigger depending on the size of tank.

      • Bryan

        Rain water on its own does not contain the good minerals that betta fish need. Rainwater absorbs these from the ground/rocks/dirt/sand etc and it’s out of the recommended pH range with average rain water pH being around 5.0-5.5. Based on this information, no, it’s not a good idea to use rain water.

  2. Shirley

    I have a four year old Betta who lived three years in a small unfiltered tank before I adopted him. He’s acting sluggish, rests on the bottom a lot. Wondering if he’s bored, unwell, etc. Loves to eat, can’t wait for the next meal. Bloodworms, beef heart, brine shrimp. I’ve set up a filter system, but am unsure of when and how to do water changes. It’s a four gallon tank. I’m tempted to go back to unfiltered. ?????????

    • Bryan

      Four years old is an older betta fish and they will get less active as they get older, that’s perfectly normal. I would do roughly 25% water changes/cyclings 1-2 times a week in the filtered tank. Our care page has more detailed information too.

  3. Maria

    Hey i just got a new Betta fish and I’m wondering if I can put purified drinking water and a bit of salt water in the tank.

    • Bryan

      I would do a test on the purified drinking water to make sure the pH is suitable among other important parameters. Also, you can add a small amount of aquarium salt following its instructions as it does help alleviate stress and other ailments.

  4. Melon

    Tap water PH fluctuates a lot. Straight out of tap GH 3 KH 1. Low KH could explain my PH being inconsistent. It’s bad for the fish and I think the readings are just too low. What products is best to remineralise or recondition my tap water. I also have RO unit I use for my shrimp keeping. I can use RO and remineralise. I’m ready to invest in remineraliser but there’s just too many in the market don’t know what to get. What GH KH range does Betta require? Please help

    • Bryan

      Yeah the KH and GH should be pretty much identical. If it fluctuates so much from your tap water, have you considered buying spring water in bulk? This may be cheaper than a bunch of additional products and constantly trying to get things in the correct range. GH and KH should be around 100-150 PPM on average similar to your GH reading of 3.

  5. Suzanne Ward

    I have a 4 1/2 year old Betta in a 10 gallon tank. Our tap water here in San Diego is terrible so I’ve changed to R/O. How much tap water should I add back in?

  6. Ash

    I was wondering if it was better and safe to boil my tap water to use for my tank after it cools?

  7. Anonymous

    What if you don’t have the water the Betta needs? Can I just use sink water and add water conditioner?

    • Bryan

      That’s usually the best approach, so long as your tap water has the proper pH and is clean/safe.


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