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4 Reasons to Add Borate in Your Swimming Pool or Spa

Borate prevents pH drifting, which results in calcium scaling, metal stains, cloudy water, algae, and hard pool water.

Borate prevents pH drifting, which results in calcium scaling, metal stains, cloudy water, algae, and hard pool water.

Do I Need Borate in My Pool?

The more chemicals you add to your pool water, the more it becomes difficult to maintain. So you should only use chemicals in your pool for specific purposes.

You need borate (borax) only for two main reasons. One of them is when you are fighting unstable pH that keeps drifting up or down for any reason. The second reason is that you need to raise the pH in your pool without affecting TA levels, since balancing pH and TA without affecting each other is always a problem.

For any reason you use borax in your pool, there are a few added benefits like softening your water and preventing metal stains and corrosion, among many more.

The main purpose for using borate in a swimming pool is for easy maintenance, because it works to stabilize the pH in a pool or spa, preventing pH-related problems.

It plays a very important role in having an easy-to-maintain and trouble-free swimming pool, especially when fighting pH-related problems.

Most pool problems are consequential, and they start with imbalanced pool chemicals, particularly pH, TA, chlorine, and cyanuric acid.

pH is the most basic and important chemical in water since all chemicals added in the wrong pH concentration will not work for your pool.

Drifting pH has lots of potential risks. If your water is full of metals or you have saltwater that has unstable or drifting pH, you should use borate to prevent pH-related pool issues like metal stains, corrosion, cloudy water, calcium scaling, and algae growth.

Borate should be used in a concentration between 30–50 ppm. Before adding it to your water, however, you need to test your pH and reduce it using muriatic acid if it's higher than 7.8.

You need to test and lower the pH, because borate raises it. But it will be more stable within the recommended range of 7.2–7.8 without drifting a lot when you add borax.

Below are added advantages you get when you use borate to stabilize your pH.

Adding borate in the swimming pool.

Adding borate in the swimming pool.

The Importance of Borate in a Swimming Pool

Here are some benefits to adding borate to your pool.

1. It Helps Stabilize pH

Firstly, when the pH drifts up beyond the maximum recommended level (which is 7.8), chlorine will not be effective in killing harmful bacteria and other organisms such as algae; which in most cases will result in green, yellow, or black water, depending on which kind of algae you have.

Secondly, when chlorine becomes ineffective, it will not function as a sanitizer, and this will definitely result in milky white or cloudy water

Moreover, high pH levels will result in calcium scaling, which builds on pool surfaces, waterlines, and accessories, especially in saltwater.

Finally, high pH can trigger health issues such as burning eyes and nose and dry, itchy skin and scalp.

On the other hand, when pH goes down below the recommended level, it will erode pool parts, causing damage to the plasters and grouting. Low pH also corrodes the metal accessories, such as steps and heater, and this may also result in metal stains and water discoloration from corroded metals.

Since borates keep pH under control, using them will prevent all the mentioned problems resulting from unstable and drifting pH. It will also mean easier maintenance since you will not need to use as many strong acids and soda ash to reduce and raise pH levels, respectively, when out of balance.

2. It Helps Prevent Algae

This is absolutely true. Since borates keep pH under control, the effectiveness of chlorine will not be tampered with, and this means that algae will not thrive in your water.

3. It Reduces Chlorine Usage

Too much chlorine has been associated with skin cancers and other harmful diseases. Moreover, the byproducts of chlorine that accumulate in the water are even more dangerous than chlorine itself.

Since free chlorine is not consumed at a high rate when pH is stable, you will not have to shock your pool often.

4. It Makes Sparkling and Soft Water

When you use borate, the water will remain clear for a long period since chloramine (or combined chlorine) does not form quickly as compared to a pool without a borate agent. Most borate agents available on the market today have chlorine stabilizer in them (cyanuric acid) which keeps chlorine from being consumed by UV light from direct sunlight. They also contain components that help to soften hard water that causes dry skin and red, itchy eyes.

What Are the Downsides of Using Borate in the Pool?

I have used borate for more than five years now, and I have not had any problems worth raising an alarm about, but here are some possible drawbacks:

  • Some pool managers might avoid the additional expense (without weighing the advantages).
  • There has been some concern that borates are toxic when taken by pets such as dogs and cats. (However, I consider this to be carelessness as opposed to side effects of the chemical.) For the record, there is no pool chemical that is not toxic when consumed and extra care needs to be taken to avoid consumption by humans or pets.

Which Is the Best Borate to Use?

Borates are available on the market in form of tetraborate decahydrate or pentahydrate, and the most common in the market today are:

  • Proteam's Supreme Plus
  • Bioguards Optimizer Plus
  • Poollife Endure
  • Guardex Maximizer
  • 20 Mute Team Borax

20 Mule Team Borax is preferred by most people due to its lower cost. Also, you can use it to raise the level of pH without increasing the total alkalinity (TA) level, which is a plus when you have low pH and you need to raise it without raising TA in your water. However, the only downside of 20 Mule Team Borax is that when used as a pH stabilizer, you will have to use a strong acid such as muriatic acid along with it to lower pH, which may cause more problems in alkalinity level.

How to Add Borate to Your Pool

Here is a step-by-step breakdown for properly adding borate to your pool.

Step 1: Add the Borate

I recommend Supreme Plus since that’s what I use and it’s superb. Even though the alternative Salt Support has cyanuric acid in it (I always feel that will bring more complications), it’s a good product and you can use it if you don’t mind balancing cyanuric acid levels.

  1. With your pump running, add the recommended level of Supreme Plus (or Salt Support) according to the volume of your pool by dumping it all the way around the pool or through the skimmer, whichever method you are comfortable with.
  2. Brush down the sides of your pool all the way around to create currents to mix it up faster. (By the way, this kind of stirring is what we should be doing every time we add any chemical into the water.)

Step 2: Run the Pump for 24 Hours

Let your pump run for 24 hours, as this will speed the process of completely mixing the chemicals.

Step 3: Test Your Water

After 24 hours, you need to test for borate, pH, and TA to make sure that they are all within the recommended range. Borate should be reading around 50 ppm and between 7.4–7.6 for pH.

Step 4: Continue to Test Borate Levels Monthly

You need to test on a monthly basis and adjust to the recommended level of 50 ppm. Even if you backwash frequently, you will need to test and adjust on a regular basis.

Step 5: Enjoy

Enjoy a sparkling, soft, algae-free water with stable pH, reduced demand for chlorine, and lower chances of calcium scaling and metal staining.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

Question: If I have a 14000-gallon pool and it’s totally green, how much borax should I add?

Answer: A green pool means the presence of algae. You don't get rid of algae using borax. You need to super shock the pool using liquid chlorine until the greenness is no more.

Question: Are borate levels higher than 50 ok? I need to add borates to increase pH without increasing TA, and my borate level is already at 50 ppm.

Answer: With borate level of 50, your pH should be stable. You don't need much borate in your pool water since you cannot get it down by any means apart from a partial drain and refill and it doesn't degrade faster. I recommend you use aeration to bring up pH naturally using water fountain equipment, degasser, air compressor to create turbulence in your water and expose much of it to oxygen. Alternatively, if it is borate is higher than 50 in your water, you need to keep pets away from the pool because if they drink it they will die. Use 20 Mule Team Borax which is quality borate to raise the pH without affecting the TA and see if pH will be stable. If you get too much borate, drain and refill 1/3 to 1/4 of your Pool Water and use pH increaser instead of borate. You can lower both pH and TA using Muriatic acid If they get off the balance. Here is more on how you can balance pH and TA:

Question: do I use Borate in addition to Bromine in my pool, or does it replace the need for Bromine?

Answer: Borate and Bromine are very different in usage. Borate acts like pH stabilizer to avoid drifting in pH, while Bromine is a sanitizer which can be used in place of Chlorine normally in hot tubs or spas since it's more stable than Chlorine in warmer temperatures. So you can use all of them for different purposes.

Question: What is the recommended amount of borate per 10,000 gallons in your swimming pool?

Answer: The most accurate method to know the reading of any chemical in your pool is to take the reading: Borate should read between 30 and 50 ppm in pool water, so have a reliable test kit for this to work for you. Also, you will find measurement indicated by the manufacturer may be in the package or on a special instruction sheet giving a clear direction on how to add borates in your pool and the correct amount to add.

Question: Just got water balanced. Started with high PH and high TA. I am planning on using Nature 2 and also wanted to add borate. I am concerned that this could create a problem due to copper in the Nature2 reacting with the borate and staining. What are your thoughts on this?

Answer: Products with copper components are not good for your pool because in the long run, you will be fighting metal stains when copper is oxidized by chlorine. I recommend you just use 20 Mule Team Borax. I just found somewhere that 20 ounces of borax will raise pH by 0.5 in a 5000 gallons pool, hope this will be helpful to determine what amount of borax you need to add in your water.


Barack James (author) from Green City in the Sun on June 11, 2020:

You just need to bring all the chemical levels within the recommended range. Pale blue colour is sometimes normal in swimming pools due to effects of light on water you need not worry unless it's green colour that could be algae or metal stains.

Angel on June 11, 2020:

My pool is on 1000 gallons. Test strip readings are all low and the water is pale blue. I only use a chlorine tablet always. I’m inexperienced. What else do I need to do the get clear water?

Barack James (author) from Green City in the Sun on March 19, 2020:

First, you need to raise pH to the highest level of 7.8 using borax that will not raise your TA, then add muriatic acid slowly by slowly while testing pH and TA levels. Muriatic acid will reduce both pH and TA, be very careful so that your pH does not go below 7.4 when adding Muriatic acid. If your pH hit 7.4 but Alkalinity is still, raise pH back to 7.8 again and repeat the process of reducing both pH and TA using Muriatic acid until your alkalinity reach the right level that should be between 80-120ppm. Don't worry a lot about high FC level as it will reduce by itself within at least 48 hours. With high FC levels, algae cannot grow in your pool unless it reduces below 3ppm. Use hand skimmer to remove debris and then vacuum the pool to remove smaller dirt that makes your water cloudy.

Toni Legrand on March 19, 2020:

I have low PH, high free chlorine, very high alkalinity, and ok stabilizer. What should I add to raise the PH as I can tell from reading your other articles this is important for less chemical usage and less change of algae. We entering our oak pollen season and all this junk in the pool tends to promote algae.Please help. Novice with pool care.

Barack James (author) from Green City in the Sun on February 25, 2020:

Yes, you can use borax to maintain pH levels in your hot tub just like in swimming pools.

Anthony on February 24, 2020:

can you use borax in a hot tub to control PH?

Barack James (author) from Green City in the Sun on February 19, 2020:

Borate or borax does not prevent scaling, it's used to raise pH without affecting Total Alkalinity level in a swimming pool. To clear and prevent scaling, you can use Orenda SC-1000, which you can find on

Susie on February 19, 2020:

I would like to use borax to prevent scaling, along with other benefits,. Scaling primarily, which has been a problem in the past.

My pool currently has balanced chemicals. How do I start?

Barack James (author) from Green City in the Sun on July 11, 2019:

You can use Insta Borate test strip by LaMotte. search it on Amozon.

grady courson on July 11, 2019:

i have never seen a test kit to test for Borax. Does Taylor have one

Barack James (author) from Green City in the Sun on May 06, 2019:

Hello Rick! Which exactly Sodium Bicarbonate are you using to raising the Total Alkalinity (TA)? Some bicarbs are not quality and not recommended for use in the pool because continued use will cause the pH and Alkalinity drift higher frequently and Calcium scaling above the recommended range and balancing them is a hustle. I guess you already have Alkalinity issues and that is why you are using lots of bicarbonate and acid lately.

I recommend you strickly use quality Alkalinity increaser like In The Swim Alkalinity Increaser to raise the TA, pH increaser/reducer to balance the pH, and SunnySide Muriatic acid to lower both TA and pH when both high, here is more about balancing TA and pH:

rick wodlarski on May 06, 2019:

Hello Barack, Lately, we have seen a drastic increase in our use of acid and bicarb in our high school pool. Pool use has dropped off since the end of the swimming season here. We've added 350 lbs of bicarb in the last six days to just maintain a total alkalinity of 80-90 PPM. Any thoughts?

Barack James (author) from Green City in the Sun on May 20, 2018:

Hello Steve. You will need 3 lbs of borax per 1000 gallons.

steve on May 20, 2018:

how much borate should be added per 1000 gallons?

Barack James (author) from Green City in the Sun on February 23, 2018:

Hi John, Borate should be kept at a level between 30 ppm and 50 ppm or slightly above 50 ppm. Too much borate may not show immediate effect but with time the pool will develop problems with other chemicals such as pH and TA. It's main use is to stabilise the pH so just keep borate within their range.

John on February 23, 2018:

What are the effects of having a borate level of 80-90ppm?