What Type of Water Do Betta Fish Need? (Ideal Water Parameters)

Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: May 7, 2024
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Betta fish, recognized for their resilience and elegance, rank among the prime freshwater species, presenting an excellent option for those initiating aquarium care. Nonetheless, ensuring proper water conditions is vital to maintain your Betta’s health and appearance. Subjecting them to unsuitable water conditions could lead to stress, illness, or potentially, death.

Article Summary

  • Betta fish don’t need a special type of water but require water free from chlorine, chloramine, added chemicals, heavy metals, and pesticides.
  • Most tap water contains chlorine and chloramine, which are harmful to fish, so it needs to be dechlorinated before use.
  • Other acceptable water sources include spring water, well water, reverse osmosis water, and certain brands of bottled water, with proper preparation.

If you’re not sure what kind of water to use for bettas, read on! I’ll be going over everything you need to know about betta fish water conditions and what type of water do betta fish need to help you raise happy, healthy fish.

What Kind of Water Do Betta Fish Need?

Betta Swimming Near Bottom of Tank
Betta Swimming Near Bottom of Tank

The kind of water betta fish need is tap water that has been dechlorinated with the right conditioner, such as API Water Conditioner.

Spring water, well water, reverse osmosis water, and some brands of bottled water can also be used with a bit of preparation.

Your betta’s water should have pH levels between 6.5 to 7.5 and hardness of around 5 to 20 dH.

Do Betta Fish Need a Special Type of Water?

Siamese fighting fish don’t need a special type of water – they simply need water that is free from chlorine, chloramine, added chemicals, heavy metals, and pesticides.

While you can purchase bottled spring water or betta specific water, tap water that has been treated with a dechlorinator is completely safe for bettas.

Types of Water

There are many types of water for betta fish you can use, but some are better than others. I’ll be going over the most common water types for bettas below, as well as addressing each one’s advantages and disadvantages.

Tap Water

The easiest and cheapest type of water to use for your betta fish is tap water, but its quality and safety depends on your location and where it’s sourced from. If your tap water comes from a municipal water source, it will usually be disinfected and be free of most types of bacteria.

That said, some tap water can harbor significant amounts of iron and magnesium or low levels of ammonia or asbestos, all of which can severely harm your fish

Chlorine and Chloramine

Additionally, the majority of tap water contains chlorine and chloramine, which are both used as a decontaminant. Chlorine and chloramine are extremely toxic to fish and good bacteria in your tank, so you’ll need to dechlorinate tap water with an aquarium water conditioner before adding it to your fish tank.

Alternatively, you can let tap water sit for at least 24 hours with an airstone to allow for chlorine to evaporate. Chloramine doesn’t dissipate from water like chlorine does, so you’ll need to use a water conditioner to remove it.

Tap Water Benefits

The main benefit of tap water is its convenience as you can access it straight from home. It’s cheaper than buying reverse osmosis water, specialized betta fish water, or a reverse osmosis system.

However, untreated tap water is unsuitable for betta fish as it often contains chemicals like chlorine and chloramine that can severely harm or kill aquatic life.

What’s in Your Tap Water?

As mentioned earlier, it’s important to know what’s in your tap water so you can ensure it’s safe for your betta fish. Most municipal water sources contain chlorine, chloramine, among other chemicals, which can be deadly to fish.

You can test your tap water using an aquarium testing kit to check its pH, hardness, ammonia, nitrite, and nitrate levels to make sure it’s appropriate for betta fish. The majority of water conditioners will remove chlorine, chloramine, and heavy metals.


If your tap water contains ammonia or nitrite, you will need to use a complete water conditioner that can neutralize these like Seachem Prime.

Distilled Water for Betta

Green Betta in a Small Tank
Green Betta in a Small Tank

While you may have heard tales of distilled water being suitable for fish, this can’t be further from the truth. Distilled water is harmful to betta fish unless it is remineralized beforehand.

Is Distilled Water OK?

Distilled water should be avoided for betta fish as it lacks minerals such as iron and calcium, both of which help your pet thrive. In fact, distilled water can lead to serious trauma caused by osmosis in fish as they have a selectively permeable membrane.

Bottled Water and Spring Water

Bottled water and spring water can be a decent option for betta fish as, unlike distilled water, it has not been treated to remove minerals and nutrients like iron and calcium.

There are 3 different types of bottled water: bottled spring water, filtered water, and purified water.

Bottled spring water for betta fish is the safest option, but make sure you check the type of minerals and nutrients it contains, as well as its pH and hardness levels.

Bear in mind that bottled water, particular spring water, is more pricey than tap water and most types will have a low or acidic pH level. You will need to test the bottle water using an aquarium testing kit before adding it to your betta’s tank.

Some brands may also contain chlorine, which will need to be removed with an aquarium conditioner.


Alternatively, you can use betta specific water, which should be available at your local pet store. Betta specific water is dechlorinated, ammonia-free, and pH balanced, so it can be added straight to your tank without any extra preparation.

Well Water for Betta

Well water is untreated groundwater and can be safe for betta fish, but this largely depends on where you live.

For instance, if you live in a rural area with a lot of farmland, fertilizer could seep into your well water during rainfall, contaminating it with harmful chemicals that could kill your betta fish.

Although well water is free from chlorine and chloramine, you will still need to test it regularly to make sure it is suitable for your betta fish.

Some areas have very hard well water like Florida and Arizona, while others have extremely soft well water like New York.

Reverse Osmosis Water


Reverse osmosis (RO) water is forced through semi-permeable membranes to remove 90 to 99% of harmful substances, resulting in almost completely pure water.

You can purchase bottled RO water from some pet stores or you can invest in a reverse osmosis system so you can have pure water at your own convenience.

The only downside of RO water is that it does not contain beneficial minerals and nutrients that are needed for stable pH levels and osmoregulation in betta fish. You’ll need to remineralize reverse osmosis water either by adding calcium sulfate and magnesium sulfate (ratio of 4:1) to it or buy using an aquarium remineralizer.


Aquarium remineralizers are convenient as they add minerals and hardness to RO water, making it safe for fish to live in.

RO water is commonly used in reef tanks and aquariums that house sensitive soft water species.

While it can be used for bettas, it’s important to note that RO water is extremely soft with an acidic pH when exposed to air.

Soft Water

Housing bettas in soft water can increase their risk of developing bacterial infections. Some aquarists mix a small amount of RO water into tap water if the latter is very hard to help soften it and stabilize the pH, but if your tap water is naturally soft, a RO system probably isn’t necessary.

Additionally, RO units can be quite pricey and will waste a lot of water, so unless you have other tanks and fish that could benefit from this type of water, an RO system isn’t particularly vital for bettas.

What Is the Best Water for Betta Fish?

The best water for betta fish is tap water that has been treated with a water conditioner to remove chlorine, chloramine, heavy metals, and other harmful chemicals.

Alternatively, you can purchase specially designed betta water from most fish stores, but bear in mind that this can be pricey, especially in large betta fish tanks.

Best Water for a Beginner Betta Fish Aquarist

The best water for a beginner betta fish aquarist is tap water due to its convenience and affordability.

However, if your budget allows it, you can use bottled betta fish water, which should be available to buy at your local pet store.

How Much Water Does a Betta Fish Need?

Betta in a Fish Tank
Betta in a Fish Tank

Betta fish need at least 5 gallons of tank water, ideally a minimum of 10 gallons, as this gives your pet plenty of space to swim around in.

Additionally, larger tanks are easier to maintain than smaller ones as there is more room for error. It’s also easier to keep your tank water parameters stable.

Water Parameters

Bettas thrive in neutral waters with a pH value of 7.5, but anywhere between 6.5 to 7.5 is sufficient for this fish.

While they prefer soft water, bettas can withstand a GH (general hardness range) from 5 to 30 dH or 70 to 300 ppm.

Water Temperature

Betta fish thrive in temperatures between 75 degrees to 80 degrees Fahrenheit as they originate from tropical waters in Asia.

Unless you live in a warm climate, you should invest in a water safe fish tank heater to keep your pet’s fish tank water at an appropriate temperature.

Water Heater

Water safe heaters can be found at your local pet store or online. You should also use a water safe thermometer so you can keep an eye on your betta fish tank’s temperature at all times.

Betta fish living in overly cool waters will result in stress and a weakened immune system, which makes them more at risk of contracting illnesses and diseases.

On the flipside, if your betta water is too hot, it will increase their metabolism and decrease their lifespan.

What’s the Most Preferred pH Level for Betta Fish?

The right pH for betta fish is between 6.5 to 7.5, but ideally around 7.5. Bettas do best in waters with a neutral pH.

Fortunately, most tap water has a pH around these values, but make sure you test your water beforehand with aquarium test strips.

If the pH isn’t right for your betta fish, it can cause shock, which is often fatal. It can also lead to your betta losing appetite or just staying at the bottom. You can lower the pH of the water by adding driftwood, peat moss, Indian almond leaves, or by using aquarium pH reducing solution products.


If you need to raise the pH level of your betta’s tank, add 1 teaspoon of baking soda for every 5 gallons of water.

Things To Remember Before Adding Bettas To Water

Before you add your new betta to your fish tank, here are a few things to keep in mind to ensure the process goes as smoothly and safely as possible.

How Long Should Water Sit Before Adding Betta?

Ideally, your betta fish tank should have successfully undergone the nitrogen cycle before adding your fish, which can take anywhere from 2 to 8 weeks depending on factors like the amount of ammonia present in the water and the amount of beneficial bacteria already in the tank.

Water Cycling

There are two ways to cycle your tank: a fishless cycle or a fish-in cycle. A fishless cycle requires you to provide an ammonia source (fish flakes, pure ammonia, or raw fish) to the water directly to feed the developing beneficial bacteria.

Here’s a quick informative video about fishless cycle…

A fish-in cycle is exactly what it sounds like: using a live fish to cycle your tank. However, fishless cycling is a safer and more ethical option. Fish who are used to cycle tanks often die or end up with a severely weakened immune system due to stress and ammonia poisoning.


Use aquarium test strips to check for ammonia, nitrite, and nitrate. Once you start seeing nitrite, you’ll know the nitrogen cycle has started. When the water no longer contains ammonia and nitrite, only nitrates, your betta fish tank will be fully cycled and safe to add livestock.

Keep Your Water in Good Condition

Betta fish care isn’t just limited to feeding your fish, ensuring they get essential nutrients in their diet, and giving your betta toys to keep them entertained. It also includes maintenance of your betta tank. Regular cleaning is important for your betta fish tank to maintain the quality of the water and to prevent pH level drops, especially in an unfiltered tank.

For the majority of betta tanks, you should perform a weekly water change , removing around 20 to 25% of water and replacing it with fresh dechlorinated water.

Water Change Frequency

Depending on the size of your betta fish tank, and its plants and decorations, you may need to do larger or smaller water changes. For instance, if your aquarium is 20 gallons and understocked, you can most likely wait around 2 weeks between each water change.

However, if your tank is only 5 gallons and overstocked, you may need to perform water changes every few days to ensure the quality of the water for your betta doesn’t drop.

How Do You Check Betta Fish Water?

Your fish tank should be water tested at least once a week so you can check nitrite, nitrate, and ammonia levels, as well as pH levels. This should be done every couple of days in new tanks to ensure the cycling process has been successful.

It’s vital to your fish’s health that you keep up this maintenance. Poor water quality has been known to cause inactivity in some betta fish.


To check your fish water conditions, use aquarium testing strips or solutions such as API Freshwater Master Test Kit.

How Long Can a Betta Fish Live in Tap Water That’s Untreated?

Tap water that has not been treated with a dechlorinator is lethal to fish as it contains chlorine, chloramine, heavy metals, and other deadly chemicals.

If you don’t use a water conditioner for your betta tank, they will likely die within a few days.

How to Dechlorinate Water for a Fish Tank

Blue and Orange Betta Fish
Blue and Orange Betta Fish Near Aquarium Substrate

To dechlorinate water for betta fish, either use a water conditioner or leave tap water for a period of at least 24 hours.

Dechlorinating tap water naturally can sometimes take up to 5 days depending on the concentration of chlorine.

Bear in mind that chloramine can only be removed using a water conditioner as it does not evaporate like chlorine does.

How Often to Change the Water on Betta Tanks?

How often you change the water in your betta tank depends on the size of the aquarium and the stocking level.

For small containers with substrate or tanks that are overstocked, you may need to do a water change every few days.

For larger tanks that are understocked, water changes at evenly spaced intervals, such as twice a month may be sufficient.

However, most aquarists perform a 25% water change every week.

Use a Stress Coat Additive to Protect Fish

Before you add your betta to their new tank, consider using a stress coat additive. Stress coat additives contain aloe vera and other nutrients which work to reduce stress in fish and help speed up recovery from wounds and damaged tissue.

Final Thoughts

I hope I have helped, and now you know what type of water do betta fish need.

As a quick reminder, the best water for betta fish is dechlorinated tap water or specially prepared betta water.

Reverse osmosis water and certain brands of bottled water such as spring water can be used, but make sure you test any bottled water with an aquarium testing kit. Well water for betta fish can be a decent option, but you’ll need to ensure the well water does not contain any pollutants or other chemicals.

And as mentioned earlier, never distilled water for betta fish should be avoided unless it has been remineralized first as it lacks essential minerals and nutrients!

Feel Free To Share!

Thanks for reading! If you know any other fish or betta owners, feel free to share this guide.

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