Ideal pH Level For Betta Fish (And How To Get It)

Last Updated on 2023-11-08

Getting the ideal pH level for betta fish right isn’t too difficult. However, if you’re new to fishkeeping, then it’s important to know as much as you can. And if you know everything you need to know now, when something does go wrong, you’re going to be prepared. So here is the ultimate guide to maintaining the ideal pH level for betta fish!

Key Takeaways

  • The ideal pH for betta fish is around 7.0, but they can tolerate 6.5-7.5.
  • Stability in pH levels is crucial; fluctuating pH will stress your betta
  • Incorrect pH can lead to conditions like pH shock, which can be fatal.
  • Symptoms of low pH include burns, lesions, and abnormal behavior. High pH can cause algae growth and disease susceptibility.
  • Low pH can be caused by the water source, tank decorations, and the nitrogen cycle. High pH can result from the substrate, water source, fish waste, and external factors.
  • Various pH testing kits are available: freshwater aquarium test kits, pH test strips, and digital test kits.
  • Regular pH testing is essential, especially after adding new elements to the tank or changing the water.
  • Natural methods to adjust pH include using driftwood, peat moss, and Indian almond leaves for lowering, and coral sand for raising.

And if you’re not in the mood to read, why not check out the video instead!

What Does The pH Level Measure?

pH levels are a measure of how acidic or alkaline water in your aquarium is. pH levels range from 0-14. 0 is extremely acidic and 14 is extremely alkaline. 7 which falls directly in the middle is neutral which means it’s neither acidic or alkaline.

What Is The Ideal pH Level For Betta Fish?

The ideal pH level for betta fish is 7.0. However, they can survive in conditions between 6.5-7.5. Overall, slightly acidic pH is better for bettas. Your betta is also going to do a lot better in an environment where the pH isn’t fluctuating, which is extremely harmful to them.

In fact, when it comes to pH a pH which is a little bit higher or lower than ideal, will still better than a pH that is fluctuating a lot, as this will put much more stress on your betta.

What Happens When The pH Isn’t Right?

If you put a betta fish or any fish in a tank where the pH isn’t right then it’s going to be bad news. Oftentimes they’ll suffer from a condition known as pH shock. Sometimes this is going to kill them instantly, however, sometimes it may take a little longer. The good news is if it doesn’t kill them straight away then you still have a chance to fix the pH and save your betta!

Before you take the necessary action to save your betta you’ll need to diagnose them correctly. To do this you’ll need to know whether they’re suffering from symptoms caused by pH that is too low, or too high.

Even though you should be testing the pH in your betta tank regularly (which you’ll find out how to do later on), it’s still important to be aware of symptoms that are associated with low pH and high pH. Here are the common symptoms of low pH in aquariums:

Symptoms Of Low pH In Aquariums

Oftentimes there are going to be a number of different symptoms of low pH in aquariums. Not all of the symptoms will be evident in your betta himself. Some of them you will also notice from other things in the tank. Such as plants, ornaments, and other tank mates.


One of the symptoms you may notice are burns or lesions on your bettas skin. When the water becomes too acidic then it’s going to have a nasty effect on your betta. If you begin to notice burns or burn like lesions on his skin and you’re sure he doesn’t have another sickness then you should check the pH of your tank.

Snail’s Will Be Affected

Another thing you may notice is any snail shell in your tank will look more fragile. Sometimes they will stop growing and you’ll notice them having difficulty maintaining their shell. This is because, in acidic environments, the calcium in the shell will leak out.

Abnormal Behaviour

You’ll also notice a lot of abnormal behavior that is common in bettas that are suffering. For example, you may see them trying to jump out of the water, as well as swimming frantically. In more severe cases, as the acid damages their gills you’ll also notice them gasping for air.

However, be cautious when using this symptom to diagnose low pH in your betta tank. It can also be a sign of toxins in your tank or a sign that your betta is sick.

Less Ammonia

And surprisingly, one benefit of a more acidic environment is that there’s going to be less ammonia in the tank. Instead, there will be a higher amount of ammonium. While ammonia is harmful to fish, ammonium is harmless.


What Causes Low pH In Aquariums?

As well as knowing the symptoms of low pH in aquariums, it’s also good to know what causes it. Knowing what causes low pH can help you avoid it, which your betta will definitely be grateful for. Here are some of the most common causes of low pH.

The Water You’re Using

Unfortunately, sometimes the acidity of the tank can be due to the fact that the water you’re using is too acidic. If you think this may be the case then there are other options that you can use.

If you’re not sure about the acidity of your tap water you can always test it out of the tap to see what comes back. And if you find out it’s too high there are other alternatives! Here’s everything you need to know about betta water conditions.

If you think that your tap water is too acidic for your betta then there is also the option of purchasing water bottled specifically for bettas. Doing this is a great way to make sure your betta’s tank won’t become too acidic.

Decorations In Your Tank

If you have decorations in your tank, there’s a possibility they’re causing the pH level in to drop.

In, the fact this phenomenon is well known. betta keepers in the past have used aquarium decorations such as driftwood to lower the pH in their tank when it becomes too high.

Maybe a decoration you have in your tank is unknowingly doing this as well. This is most likely to happen on natural decorations, especially wood and leaves.

The Nitrogen Cycle

Believe it or not, the nitrogen cycle is slowly going to decrease the pH level in your tank, making it become more acidic. If your betta tank is relatively new then this is going to happen very fast. But, the older and more aged a tank is the slower the process is going to be, although it’s still going to happen.

This is one of the reasons people recommend 25% water changes every couple of weeks. Doing this removes some of the acidic buildups and it’s going to replace acidic water with new water.

black and red betta

Symptoms Of High pH In Aquariums

If the pH in your betta tank is too high then it’s going to be too alkaline. Just like when it’s acidic, there are going to be certain signs and symptoms evident of this. And while some of these symptoms are similar, some are different.

Algae Growth

One of the biggest signs of high pH in your aquarium is a sudden bloom of algae growth. If you notice this happening then you should test the pH of your tank. However, an increase in algae can also occur when there is too much light in your tank.

So along with algae growth, you should also look for other symptoms as well.

More Diseases

If your betta is being housed in a community tank then you may notice symptoms of disease on more of your fish. Diseases like ich are more likely to occur in tanks that have a high alkaline level. If you notice the symptoms of ich, as well as treating your betta immediately you should test the tank water too.

If you’re not sure what the symptoms of ich look like, or if you want to find out more then why not read about everything you need to know about ich!

Abnormal Behaviour

And of course, just like when the environment is too acidic, when it’s too alkaline your betta will begin to act strangely. Often referred to as alkalosis.

If your betta is suffering from alkalosis you’ll notice that he is swimming chaotically and erratic (a tell-tale sign of illness). In an attempt to stop their skin from being hurt from the alkaline they may also scratch themselves on ornaments and try to jump out of the tank.

You’ll also see your bettas fins spread wide apart and excess mucus being secreted from the gills. This excess mucus is an attempt to stop the high alkaline water damaging his gills.

Of course, the best way to know for certain whether the water in your tank is too acidic or alkaline is to test it with a pH kit. (Which you’ll find out how to do later.)


What Causes High pH In Aquariums?

Just like low pH, you can normally spot the causes of high pH in your tank and change them. And if you take action, then you can reduce the pH level back to neutral for your betta.

The Substrate You’re Using

One big cause of high pH in betta tanks is the substrate you’re using. While it looks pretty coral sand has large amounts of calcium in it. Over time the calcium can leak out of the coral sand and into the water increasing the pH.

That’s why coral sand and similar substrates are not recommended for betta tanks. Although they may be better suited in saltwater tanks.

If your tank’s substrate is coral sand then you should change to something such as gravel or sand.

There’s a lot to know about the different substrate types for bettas, so you should read as much as you can on the subject.


Once again the water you’re using could be directly affecting the pH. In areas, where there is a buildup of calcium and other minerals, it’s more likely the pH level is going to be higher.

If you think this is happening to you then you should avoid using tap water. Try using bottled spring water but avoid distilled water. Distilled water has had all the minerals and nutrients taking out that your betta needs to survive.

Fish Waste

Urea which is commonly found in fish waste is known to raise the pH in betta tanks. If you’re not using a filter in your tank then over time the pH of the tank will slowly rise.

This is one of the reasons it’s so important to have a filtration system in your tank. However, there are many more reasons it’s important too.

Along with fish waste, food particles are also going to play a part in the pH level. So make sure you’re cleaning your tank regularly!

External Sources

And lastly, another common cause of pH rising in your tank is external sources being introduced. If you’re placing your hands, fish bags, decorations, or anything new into the tank then there’s a chance the pH in your tank could rise.

While this is less likely to cause it than the other two, it is a reminder that you should only be putting things into your betta tank when you absolutely have to.

pH Level For Betta Fish

How To Check The pH Level Of Water In An Aquarium

Knowing the symptoms of pH changes are a great way of noticing when something is wrong. But it’s still a crude method that isn’t going to give you the best results. If you really want the best ways to check the pH level of water in an aquarium, then the first thing you’re going to need to do is a buy a pH testing kit!

Different Types of pH Testing Kit

There is a range of different pH testing kits you can use to test your betta tanks water. Some of them are basic and easy to use, but won’t give as good results. While other’s require a bit more knowledge but can give you much more accurate results! Here are the different test kits you should consider using.

Fresh Water Aquarium Test Kit

Freshwater test kits are what I like to use and the API Master Test Kit is actually the test kit I own! It’s great because not only does it come with a pH and High pH test, it also contains ammonia, nitrite and nitrate too!

While I would love if it had a KH and GH test kit, unfortunately, it doesn’t. But if you’re just getting started, this is going to work great in your tank!

Freshwater kits can tell you with a degree of accuracy what the pH of the water is as long as it’s between 6.0-7.6.

As well as testing pH, the bigger freshwater test kits also allow you to test to the ammonia, nitrite and nitrate levels as well!

One of the biggest benefits of freshwater aquarium test kits is the low price. I use the API Master Test Kit.

API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, White, Single, Multi-colored
  • Contains one (1) API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, including 7 bottles of testing solutions, 1 color card and 4 tubes with cap

pH Test Strips

You may have heard of litmus paper before, or even done science experiments with it at school. If so, then you’re going to be familiar with it. All you have to do is dip the litmus paper into a sample of your water, and depending on the color you’ll know how acidic or alkaline the water is.

The problem with test strips and why many people don’t use them is because they’re too broad and inaccurate. Normally you’ll notice large jumps between the intervals you’re trying to measure.

So while they’re good at giving you a rough idea at what the pH in your tank is, after using them you’ll still need to test with something more accurate.

Digital Test Kits

If you want the most accurate type of test kit then digital test kits are the one for you. Normally they’ll be able to tell you the pH down to 0.1.

And all you have to do is dip the test kit into a sample of your water and wait for the reading.

While they cost a little bit more than the other two (around $30) they’re also going to have an added benefit of lasting a lot longer. They’re also not going to expire over time which will happen with the other two types.

So if you’re planning on keeping bettas for a long time then a digital test kit is the way to go.

Divolight Water Tester PH Meter, Digital PH Meter 0.01 PH High Accuracy Water Quality Tester with 0-14 PH Measurement Range for Household Drinking, Pool and Aquarium Water PH Tester Design with ATC
  • 【Aplication】As a tool to improve the quality of life. Can be used to test drinking water, swimming pools, PH balance in an aquarium, RO system, spa, or hydroponics. All the environments that need to test PH values can use this tester to get accurate data.

Testing For The Ideal pH For Betta Fish

Now that you know what kind of kit you’re going to use the next step is testing the water. The way you test the water is going to depend on what type of kit you’ve brought. Here are the different methods you’re going to have to use.

Testing MethodsUtilize freshwater test kits, pH test strips, and digital kits for pH assessment in betta tanks.
Frequency of TestingRegular testing recommended, especially after any alterations to the tank or water changes.
Importance of TestingMonitoring pH crucial to maintaining betta health. Detects fluctuations and prompts timely adjustments to ensure stable levels.
Testing ProceduresSpecific instructions for using different testing methods (e.g., test kit components, sample collection, reading the results).
Relevance for Betta Well-beingUnderstanding pH levels critical for betta health and vitality. Detects shifts in pH that might affect the fish adversely.

Using A Fresh Water Aquarium Test Kit

Using a freshwater test kit may seem daunting when you open the box, but when you know what you’re doing it’s going to be a piece of cake.

First of all, you’re going to want to unpack everything. In most cases you should have the following:

  • Test Tube
  • Color Chart
  • pH Solution (What you’re going to add to the water for it to change color)

Once you’ve unpacked everything you normally take a sample of water from your tank and put it in your test tube. Once in the test tube add the pH solution. (How much you add depends on the manufacturer, so read the instructions.)

Once everything has been added to begin shaking the test tube for a good amount of time.

As you shake the tube you’ll begin to notice the water slowly changing color. And keep shaking the tube for however long you’re instructed too

And finally, using a color chart, inspect the water under a bright light so you can see the color clearly.

Using A Strip Test

With a strip test, the process is generally the same. However, you’ll stick a strip of test paper into the test tube as well. Then when the strip paper changes color, you’ll know the pH of your tank.

Using A Digital Test Kit

And, if you think using a digital test kit is your best bet, then here’s the general process for most test kits.

Using a digital pH test kit is even easier. All you have to do is take a sample of water from your aquarium.

Once you’ve done this turn the test kit on and begin swirling it around the water for the designated amount of time. When the time is up you’ll have a reading on the tester with the pH of your tank.

On some test kits you’ll also have to dip your test kit into a solution beforehand to calibrate it, however, on newer models this doesn’t happen as often.

It’s Important To Remember

  • You shouldn’t only test the water in your aquarium when you think there’s something wrong. It’s always best to check at least once a week (but in the case of new tanks even twice). Doing this you’re going to be able to spot any changes in pH before they begin to affect your betta.
  • You should also test the pH of your aquarium if you’ve added anything new. New additions to the tank (even decorations) can cause the pH to shift).
  • And you should test a couple of times after you’ve changed the water. This is one of the times when it’s extremely likely the pH in the tank will shift.

How To Raise/Lower The pH In Your Betta tank

If you’ve tested the pH in your tank and it’s come back too high or to0 low then obviously the next step is to change it. However, the way you change the pH level in your betta tank is going to depend on whether it’s too high or too low.

First of all, we’ll start with how to lower the pH. Generally, bettas can survive longer in conditions that are more acidic than alkaline.

Change The Levels Naturally

You can raise and lower the levels in your tank naturally. The benefit of this is that it’s not going to be as expensive and there aren’t going to be any chemicals added to your tank!

How To Lower The pH Levels Naturally

Items like driftwood, peat moss, and Indian almond leaves are all great choices. Just make sure you prepare them properly first!

Remember, when using any of these items it’s important not to cluster them together. Try to spread them out so they pH lowers quicker.

Similarly to lower the pH in your tank you can also raise it in a similar fashion.

Remember, that driftwood will still need boiling before you add it to your tank. If I want to keep the tannins that lower pH then I only boil it for a couple of hours, however, when I want to leech the tannins out I boil it for a couple of days.

emours Aquarium Driftwood Fish Tank Decoration Varies Shape and Size (Medium)
  • Made of high grade driftwood, solid and durable, long lasting in underwater or arid environments

Naturally Raising pH Levels

To naturally raise the pH levels in your tank is going to require different ornaments for you to us.

One of the best things you can use is coral sand. Coral sand is going to leak calcium into your tank which will slowly raise the alkalinity of your tank.

As well as coral sand you can also use other rocks that are high in calcium such as limestone.

Estes Gravel Products AES51510 Este Crushed Coral for Aquarium, 15-Pound
  • Formulated for Russian, Greek, Sulcata, Leopard and Pancake Tortoises. Added vitamins and minerals; No artificial colors or preservatives.

Cleaning The Tank

You should be doing this anyway. But one of the best ways to keep the pH at the right level is to clean your tank regularly.

Specifically changing the water and cleaning the gravel. When you do this you’re going to remove any substances that could cause the water to become more acidic or alkaline, such as feces, rotten food etc.

You should also remove any algae off the sides of your tank and decorations as well as making sure that the filter is clean.

Here’s a full guide on how to clean your tank.

Tetra Whisper IQ Power Filter 20 Gallons, 130 GPH, with Stay Clean Technology
  • QUIET AQUARIUM FILTER: The Tetra Whisper IQ Power Filter with Stay Clean technology contains a sound shield for quiet filtration less than 40 dB.

Remove Dead Fish And Plants

This goes without saying but the moment you notice something dead in your tank you should remove it immediately. Anything decaying in your tank is going to cause the ammonia levels to spike which in turn can increase the pH of your tank.

Get A Reverse Osmosis Filter

This is the most expensive option and normally isn’t necessary for smaller tanks. However, if you have the money to spare then it’s well worth the investment because it’s going to keep the water super clean.

Reverse osmosis filters work by running all the water through them removing any water pollutants from it.

They come in different sizes, and the bigger the size the more powerful the filter.

Bluevua RO100ROPOT Reverse Osmosis System Countertop Water Filter, 4 Stage Purification, Counter RO Filtration, 2:1 Pure to Drain, Purified Tap Water, Portable Water Purifier for Home
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Try Aerating The Water More

Another great solution is to make sure you’re aerating your water. The more oxygen you can add to your tank the more stable the pH will become over time. And it doesn’t have to be a difficult process! Just add an air bubbler to your tank.

Pawfly Aquarium 30 GPH Compact Air Pump Quiet Oxygen Aerator Pump with Air Stone Airline Tubing and Check Valve Accessories for 5-20 Gallon Buckets and Fish Tanks
  • Compact & Light: Measures 3.3″ L x 1.8″ W x 1.6″ H. Ideal for those who are tight on space. Suitable for 5 – 20 gallon fresh and marine fish tanks and aquariums.


Lastly, remember, when changing the pH levels of your tank you want to do it gradually and not too quickly. Doing it too quickly is one of the quickest ways you can cause your betta to get pH shock. Which is often fatal.

Looking for a comprehensive guide about how to take care of your Betta fish? Click here!

pH Level For Betta Fish

Conclusion – The Ideal pH Level For Bettas

As you now know the ideal pH level for bettas is as close to 7 as possible. However, knowing the ideal level isn’t going to be enough. You’re also going to need to know a lot to keep it neutral. Here are a few of the main things you’re going to need to remember:

  • Even though the best pH for a betta is 7, it can survive in slightly more acidic conditions.
  • Keeping the pH in your tank steady is just as important as keeping it as close to 7 as possible.
  • Symptoms of low pH are burns, lesions, snail shells becoming weak, and abnormal behavior such as swimming frantically and jumping out of the water.
  • Symptoms of high pH include a lot of algae growth, fish getting more diseased, and swimming chaotically, scratching themselves on ornaments, spread fins, and mucus on the gills.
  • Low pH and high pH are often caused by the tap water you’re using being too acidic or alkaline, decorations in your tank causing it to become too acidic or alkaline, the nitrogen cycle, fish waste, and external sources.
  • You can use chemical test kits or digital test kits to test the water.
  • You can raise and lower the pH naturally with decorations, cleaning the tank, removing anything dead, aerating the tank, or getting a reverse osmosis filter.


Ultimate Betta Fish Care Guide
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