Betta Fish Water Guide: Ideal Types, Parameters & Maintenance

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Last Updated: September 29, 2023 by Flora Gibbins

Bettas, or Siamese Fighting Fish, can tolerate a wide range of water chemistry parameters. Depending on the tail shape, you may need to manage betta fish water more carefully to avoid disease.


If you decide to start your aquarium-keeping hobby with bettas, you will get an excellent grounding in water chemistry that can easily be applied to other tropical freshwater fish. 

Tap water for betta fish


When it comes to answering the question “What kind of water for betta fish should I use?”, I often wind up saying it’s more about the quantity of the water as opposed to the type.

If you have more water in the fish tank, you will also need stronger filters to keep it clean, thus ensuring a healthy and happy betta environment all the time.

Except for Plakat and Spadetail bettas, just about every other variant has excessively long tails and fins. This makes it very hard, if not impossible for them to swim in waters with strong currents. 

Since you are likely to be working with smaller amounts of water, being able to control the parameters is critical. 

From feeding amounts and timing to water changes, choosing the water for betta fish is mainly about how you will take care of the water and the fish daily.

How to Make Just About Any Type Of Water Safe for Bettas

I tend to think of creating the best water for betta fish as a process as opposed to just one step.

Here are the basic steps:

  • Choose a water type
  • Research and identify potential chemical impurities that may be of harm to your betta fish.
  • Filter with activated carbon 24 – 48 hours before adding to the tank.
  • Add water conditioner specifically made for aquariums.
  • Filter for another 24 hours.
  • Test the pH and hardness. Make adjustments as needed.
  • Float the water in a bag in the tank for 30 minutes. This will equalize the temperature between the new water and existing water in the tank.
  • Release the water into the tank.

Betta Water Parameters

pH Level

Betta fish will thrive in water within a pH range of 6.5 to 7.5. Usually, bettas do best in softer water, but they will also tolerate medium to semi-hard water. 


The best betta water temperature is between 76° and 80° F (24.5° and 26.5° C).


Consistency, routine tank water testing, and observation of fish behavior are more important than adhering to narrower water parameters for betta

Consistency is key. This can be achieved with a good heater for your betta fish tank and you should check it with a thermometer regularly.

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6 Water Types for Bettas and How to Use Them

Before you bring home a new betta, you will have to decide what kind of water you will use in the tank. 

Since there are many freshwater options available, many people ask “What type of water do betta fish need?”

Here are 6 common water types that will work, and how you can make the most of them.

1. Betta-Specific Water

Many people mistakenly believe betta-specific water can be used as a shortcut for a new betta tank. 

This water doesn’t have beneficial bacteria in it. 

The only thing you are getting is plain water that has a conditioner added to it. To add insult to injury, most of this water comes in plastic bottles which may leach all kinds of petrochemicals into the water.

Betta-specific water won’t reduce the risk of ammonia surges and disease. Only proper water management can do that.

2. Spring or Bottled Water

Spring or bottled water usually goes through one or more filtering processes to ensure it is safe for human consumption.

As a result, spring water is usually fairly soft. While it is likely to have plastic residue or other chemicals in it, some consider it safer than municipal water.

I always recommend using a water conditioner with bottled water just in case there are toxic chemicals present. 

You should also use activated carbon to lock up other contaminants that may be in the water.

3. Rainwater

Rainwater is a somewhat controversial type of water to use a betta tank. Some people point to pollutants and elevated nitrogen as reasons not to use it.

I found it best to avoid using rainwater in fish tanks if it is from a thunderstorm, as that is when nitrogen levels are highest.

Other than that, it is soft water that can be very refreshing for the fish. Just be sure to test the water parameters and adjust as needed. 

As with spring water, you may still need to filter through activated carbon.

4. Distilled Water

Distilled water has had all its minerals removed. In this case, it’s not a good thing. Your fish needs these basic minerals to stay alive.

I don’t recommend distilled water for starting a betta tank or routine topping off. 

It can be of use in emergencies where the pH is too high or low. You can also use it to reduce the hardness quickly.

5. City Or Municipal Tap Water 

Because it is cheaper and readily available, many people ask “Can betta fish live in tap water?”. 

Tap water can be used as long as you condition it properly. 

To ensure city water is free of disease-bearing organisms, the water is treated with chlorine, chloramine, or a similar chemical.

Chlorine-based chemicals are deadly to tropical fish. You can purchase a water conditioner that will neutralize these chemicals and make them safe for the fish.

Depending on where you live, the local water supply may also need adjustments to the hardness and pH. 

You should also consult the water advisory reports to see if there are various toxins in the water that might harm your betta. 

As you can see in this video released by the US Environmental Protection Agency, groundwater is susceptible to sources of contamination that you may not be aware of.

In most cases, activated carbon in the filter should be sufficient to remove pesticides, pharmaceutical drugs, and other chemicals in the water. 

I also recommend using a water conditioner that binds to heavy metals and moves them to a place where they no longer circulate in the water. 

If the water is heavily contaminated, you may need to set up a small bowl or tank and filter the water for 24 – 48 hours before you add it to the tank.

6. Well Water

As with city water, the parameters of your well water may vary depending on the mineral content of the areas it flows through underground.

Most tap water won’t have chloramine or chlorine. It may still be contaminated from fracking, industrial, or farm-based pollution runoff into the local water table.

I recommend having your tap water tested for impurities, and then make sure you know how to filter out ones that may be harmful to your fish. 

In most cases, activated carbon will do the job. You may also need specialized resins to filter out more complex chemicals.

You should also use a standard aquarium water conditioner to bind copper and heavy metals that can be harmful to your betta.

Betta Water And Partial Changes

Some “experts” say to do a 20% water change every week, while others go as high as 50%.

All of these water changes can be very harmful to the fish for several reasons.

First, each time you take water out of the tank, you are also removing slime which is shed by the fish as it swims around. As the water ages, it becomes more comfortable for the fish.

The slime coat helps keep bacteria and other harmful organisms from reaching the scales and inner body of the fish.

Second, every time you siphon water out of the tank to make room for new water, you will stress the fish out. 

Remember, this is the fish’s only home. It sees dropping water levels as a danger to its life and well-being. 

Going through that weekly is enough to collapse any fish’s mind and immune system. They will become more prone to bashing into things and injuring themselves. 

At a minimum, they will show other signs of extreme distress such as rapid gill pumping, increased gill flaring, reduced interest in food, and erratic swimming.

Even if you are caring for betta variants that are more prone to disease, you are much better off making sure the water parameters and temperature remain as stable as possible. 

This, combined with good quality food will do more to prevent a disease outbreak than anything else.

Cycling Water For A New Betta Tank

Without beneficial bacteria, leftover food and fish waste will constantly build up. This will create high ammonia, nitrite, and nitrate levels.

Before you add bettas to a new tank, always make sure the water has gone through a cycle where the ammonia, nitrates, and nitrites rise and then fall to undetectable levels.

At this point, good bacteria will be established in the tank and ready to take on the job of breaking down ammonia and nitrates so that the water remains safe for your fish.

Do not forget to add live plants, which will complete the process by absorbing nitrates.

Check out our guide on how to cycle a tank in 24 hours.

Frequently Asked Questions

What kind of water is ok for a betta fish?

You can use just about any kind of water as long as it falls within the optimal water chemistry parameters. 

There are many water purification and conditioning options available on the market.

How do I condition and treat my betta fish’s water?

Depending on what’s in the water, you will likely pre-filter with activated carbon, and then use an aquarium-safe water conditioner to finish out the process. 

I recommend Jungle Start Right Complete Water Conditioner. It is the conditioner that I started with decades ago and still use to this day.

Unlike other conditioners, Jungle’s removes heavy metals and offers other benefits.

If this is your first fish, consider this an essential item – don’t leave the store without it.

In addition to my recommended water conditioner, here are two other options of the most popular are, Fluval Water Conditioner and Tetra Aquasafe. You’ll need to use it with every water change.

What should I look out for when adding water to a Betta Tank?

Make sure the water is safe from a chemical perspective. Next, evaluate the water parameters to make sure they match the existing tank water and the needs of the fish.

When adding new water to a betta fish tank, you should also make sure that the new water has the same temperature as what your fish is now swimming in. 

For more information on other aspects of Betta fish care, check out this article.


When I started in aquarium keeping, freshwater was far less polluted.  There wasn’t as much of a need to ask the question “What kind of water for betta fish is really safe?”.

Regardless of the water source, these days you need to pay much more attention to pollutants that can kill your fish. 

Along with using an aquarium water conditioner, you will more than likely need to pre-filter the water to ensure good quality.

7 thoughts on “Betta Fish Water Guide: Ideal Types, Parameters & Maintenance”

    1. Yeah this is a sad fact :(. A sign of a good pet store is one that would house bettas in filtered and heated water. We would recommend that you do not support the sale of bettas in any other stores.

  1. Trevor D Money

    You forgot that while pet shops typically sell Betta in small bowls, this IS detrimental to the fish! A “solo” aquarium of 5-10 gallons is best AND a quiet, slow running filter that doesn’t give a powerful current! The filter will aid in the establishment of a healthy bacteria level and although a 20% water change weekly is advisable, you won’t need to do something excessive like a 50% (or higher!) water change. ALSO, if you have the right LED lighting, REAL aquarium plants are essential to feed on the nitrate by products of the bacterial cycle and keep the water healthy.

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