Betta Fish Water Guide – Type, Temperature, and More

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Fishkeepers love betta fish and it’s easy to see why. With their stunning colors and charming personalities, these fish are a perennial favorite! 

Unfortunately, many misconceptions exist about the type of water betta fish need. For instance, many people think bettas thrive in small bodies of water when kept in captivity when this is simply not the case.

In this article, we will take a look at creating the optimal betta fish water for your new pet! Learn how to monitor parameters, change betta fish water, and more!

Wild Betta Water Parameters

In the wild, bettas inhabit shallow fresh waterways such as rice paddies, small rivers, and swamps. These bodies of water appear brown and murky from the presence of tannins, which is a byproduct formed when fallen leaves break down in the water.

Tannin is a perfectly natural (and even beneficial) component of a betta fish’s natural habitat, but the brown discoloration it causes has created the misconception that betta fish can survive in poorly maintained waters. This cannot be further from the truth. 

The reality is, tannins lend an acidic quality to water, which bettas prefer. Contrary to popular belief, bettas also require pristine water conditions – high levels of ammonia and nitrates will prove fatal. Last but not least, they are accustomed to water that is soft – this means water with relatively low levels of dissolved calcium and magnesium.

betta fish, siamese fighting fish in aquarium

Understanding the water parameters found in a betta’s natural habitat allows us to replicate these conditions in a tank. Let’s take a deep dive into how to create optimal water conditions for your betta.

Betta Fish Tank Water Parameters

Now that we’ve taken a look at how betta fish live in the wild, let’s figure out how to keep your betta happy in captivity! The first thing you should do is to check that you have all the basic supplies you need to keep your betta happy. Beyond that point, you should focus on water parameters.

It is extremely important to keep your fish tank water parameters as close to ideal as possible. This allows your fish to grow, thrive, and live a long, healthy life!

Here are the parameters to keep in mind:


Between 75 – 80 degrees Fahrenheit

Ammonia and Nitrite

Under 0.5 ppm (parts per million)


Under 20 ppm


Between 3 – 4 dGH (50 – 66.7 ppm)


Between 6.5 and 7.0


Above 3 – 5 dKH (53.6 – 89.4 ppm)


Betta fish hail from the tropics of Southeast Asia, and the temperature of their water should reflect that. The best temperature for betta fish is between 75 – 80 degrees Fahrenheit. 

Because most people keep their homes cooled to a lower temperature, you will likely need a heater for your betta tank. Water temperatures that are too high or too low will hurt your fish’s immune system, and nobody wants that!

Ammonia and Nitrite Levels 

Ammonia and nitrites are waste products that are toxic to your fish. As such, you strive to maintain a safe ammonia level in your tank at all times. A composition of 0.5 ppm is the absolute maximum if you want your fish to stay healthy.

Nitrate Levels

Betta fish have a greater tolerance to nitrate levels, so you have a little more leeway. You can have a nitrate level of up to 20 ppm in your tank. Of course, the best nitrate level for your fish is one that is as low as possible, so remember to change your water regularly!

pH Level

Betta fish enjoy water conditions that are neutral or slightly acidic. We recommend a pH level between 6.5 and 7.0, as this reflects both their preference for neutral water conditions as well as water that is slightly acidic.

General Hardness (GH)

GH measures the amount of calcium and magnesium that is dissolved in the water. Water with a large quantity of calcium and magnesium dissolved in it is known as hard water and would reflect a high GH reading.

Bettas prefer water that is soft, with a GH reading of between 3-4 dGH.

Carbonate Hardness (KH) 

KH measures the amount of bicarbonate and carbonate ions in the water, both of which affects the water’s ability to absorb and neutralize acid. In general, the higher the KH, the more stable your pH readings will be.

Bettas prefer water parameters that are consistent, which makes the role of KH doubly important. This is why we recommend a KH reading of at least 3 dKH.

How To Check Betta Fish Tank Water Conditions?

The best way to make sure that your water parameters are up to mark is to test them regularly. Many changes in water parameters are invisible to the naked eye but still play a crucial role in the health of your fish.

Here are a few ways to check the water conditions of your betta fish tank:

Test Kit

Test kits are a true godsend for aquarists as it provides a reliable way for you to check your water parameters and keep them healthy. 

Many types of test kits exist in the market, but we recommend getting a master kit that detects ammonia, nitrate, and nitrate levels. These parameters have a significant impact on the immunity of your betta, so this is well worth the investment. 

You may also want to consider investing in liquid drop test kits for GH, KH, and pH. Though there are other ways of testing for hardness and pH, test kits are one of the most popular ways to do so.

Portable pH Meters

Portable pH meters are a reliable, affordable way for you to measure the pH of your water. While test kits run out after a certain number of tests, pH meters allow you to test your water as regularly as you want to.

If you own multiple tanks, or intend to test your water frequently (as you should!), pH meters will meet your needs perfectly.


Apart from test kits, photometers are another popular way of measuring a water’s GH and KH. Photometers work by measuring the amount of light that seeps through a water sample. This in turn gives you a reading for how much calcium and magnesium (GH) or carbonate ions (KH) are dissolved in the water.

You will require separate photometers to measure GH and KH, as the physical properties of ions and solids are very different.

Aquarium Thermometers

Last but not least, aquarium thermometers are a cheap, reliable way for you to check that your water is at the right temperature. 

Because water temperature can fluctuate throughout the day, we recommend using a thermometer that can be attached to the inside of the tank. This will allow you to keep a close and frequent eye on temperature readings!

What Water To Use For A Betta Fish Tank?

Many fishkeepers wonder if their beloved bettas need special water to be happy — if you’ve ever found yourself in a similar predicament, don’t worry! This section is for you!

Tap Water

“Can betta fish live in tap water?” This is a great question, as tap water, while readily available, often contains chemicals that may be harmful to your fish. For instance, chlorine, which is used in 98% of the US water supply system, can damage your fish’s gills.

Pro Tip 

However, betta fish can live in tap water that has been treated with a water conditioner.

Water conditioners make tap water safe for your fish by neutralizing harmful substances such as chlorine, chloramines, and other volatile organic compounds. They can be purchased at your local pet store.

Bottled Water

Some people may wonder if they can house their bettas in bottled water. The answer is – it depends. 

Water obtained from springs or other natural sources can be great for your fish as they contain dissolved minerals that fish require. However, distilled water is a bad choice for this very reason – pure H2O lacks the minerals fish need to survive.

If you have decided to use bottled water for your betta, be sure to test it with a pH kit. The pH of bottled water can differ based on the manufacturer, and you want to be sure that your fish is happy in its new home.

Pre-Conditioned Aquarium Water

close up image of underwater landscape nature style aquarium tank with a variety of aquatic plants inside.

Pet stores sell pre-conditioned aquarium water for hobbyists who need it in a pinch. These are popular among individuals who lack access to other reliable sources of water. 

The key benefit of using pre-conditioned aquarium water is that it is free of the harmful substances you might find in tap water. If you’re considering using pre-conditioned aquarium water for your betta, you can rest assured that you will be providing it with a clean, comfortable biosphere.

How and When To Change Your Betta Fish Tank Water?

Knowing when and how to change the water in your betta tank is crucial to the well-being of your fish. While there are no hard and fast rules when it comes to water changes, there are several best practices that will make the process fuss-free for you and your betta:

Keep Water Parameters Stable

Small fish tank aquarium with colourful snails and fish at home on wooden table.

Drastic changes in water parameters is harmful to your betta, as they would have already gotten used to their existing conditions. Sudden, large changes in water parameters can stress out your fish and cause more harm than good.

If testing your water yields results that fall beyond the recommended range, you should make gradual adjustments to bring things under control. Slow and controlled water changes are the way to go – your fish will thank you for it!

When Water Parameter Readings Are Unhealthy

Regularly monitoring water parameters in your tank allows you to take swift action when things are less than ideal. High ammonia, nitrate, and nitrite readings in particular indicate that toxins in your tank have built up to an unhealthy level, and that a water change is due.

Conduct Weekly Water Changes

If everything in your tank is running smoothly, conducting weekly water changes will keep it that way. Tanks that are filtered benefit from weekly changes, while unfiltered tanks will require water changes that are more frequent and extensive.

When in doubt, test your water. This is the most reliable way for you to determine if a water change is needed.


Betta fish are charming, loveable pets that deserve the very best care we can afford to give. We hope this betta fish water guide gave you a good starting point in creating the perfect home for your fish! If there is a betta enthusiast in your life who would benefit from this guide, please do share it with them!

Have you ever kept betta fish as pets? What did you think of our water guide? Let us know in the comments below!

Wanda is a second-generation aquarist from the sunny tropics of Malaysia. She has been helping her father with his freshwater tanks since she was a toddler, and has fallen in love with the hobby ever since. A perpetual nomad, Wanda does her best to integrate fish-keeping with her lifestyle, and has taken care of fish in three different continents. She loves how it provides a nice break from the hustle and bustle of life.

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