How To Use Soda Ash (Sodium Carbonate) in Your Pool

Written by Michael Dean
May 22, 2023

soda ash next to a swimming pool

Maintaining the delicate pH balance of your swimming pool can be challenging and usually requires a highly specific mix of chemicals for sustained clean water. If testing the water chemistry of your pool reveals too much acidity for safe swimming, soda ash – also known as sodium carbonate – may be an excellent solution to restoring a healthy balance.

So, what is soda ash, how does it compare to similar options, and how do we use it? Let’s dive in.

Main Takeaways

  • Soda ash is an alkaline chemical that neutralizes acids and raises the pH of the pool water.
  • Soda ash is great because it affects the pH without affecting the overall alkalinity level. Baking soda is a great alternative if you need to raise both the pH and the alkalinity.
  • To add soda ash to your pool, test the water, calculate how much soda ash to add, collect some pool water in a bucket, add soda ash to the bucket, mix and dissolve the soda ash, and finally, pour the solution around the perimeter of the pool.
  • To reduce cloudiness after adding soda ash, make sure the soda ash is completely dissolved before adding it, don’t use it when also adding calcium chloride, and measure carefully.

What Is Soda Ash?

Simply put, soda ash is an extremely basic, or alkaline, chemical that can be used to neutralize acids. In other words, soda ash will raise the pH of pool water to make it less acidic. Pool owners have been using soda ash – and similar pH-balancing products – to manage the chemical composition of their pools for safe, clean water for many years.

In more complicated terms, soda ash, or sodium carbonate, is an inorganic compound that takes the form of an odorless, white, water-soluble powder or salt. Also called washing soda, sodium trioxocarbonate, and soda crystals, soda ash was once extracted from the ashes of plants. The sodium-rich soil the plants were growing in helped produce this helpful salt that created minimally alkaline solutions in water.

Because sodium carbonate is soluble, it can be used to remove both temporary and permanent hardness in water. Soda ash can remove calcium carbonate and magnesium carbonate, softening the water by essentially eliminating dissolved magnesium and calcium.

Soda ash can be purchased at almost any pool supply store and online retailers carrying pH-balancing chemicals.

I recently had to make a stop at Leslie’s pool supply store and snapped a photo of their popular soda ash product that you can use.

You can also find soda ash on Amazon and other online retailers (Leslie’s has an online store too).

In The Swim pH Increaser - Granular 100% Sodium Carbonate (Soda Ash)

If you want to order online, In The Swim makes a reliable pH increaser (a fancy name for soda ash).

View on Amazon View on Walmart
I may earn a commission if you make a purchase, at zero additional cost to you. This in no way impacts my research process or opinions.

Reasons to Use Soda Ash in Your Pool

Between the available chemicals and aeration, there are more than a few options for keeping your pool’s pH at the level it’s supposed to be. What makes soda ash a good choice for treating your particular pool?

One major advantage to using soda ash for keeping your pool clean and clear is that it affects the pH but has a minimal effect on the overall alkalinity level, making it a helpful tool for clearing up acidity without the cloudiness that comes from high alkalinity.

It’s important to keep in mind that the best pH range you can have for your pool is between 7.4 and 7.6, while the total alkalinity should be around 80 to 120 ppm. A pH of over 7.6 is too basic, and anything under 7.4 is too acidic, which is one thing soda ash is very effective at resolving. Soda ash has a pH level between 11.3 and 11.7, making it a powerful combatant for low pH levels.

Soda Ash vs. Baking Soda

Soda ash and baking soda (sodium bicarbonate) each have their unique advantages and disadvantages. Baking soda is very similar to soda ash and can be used for the same purpose, but it will have slightly different outcomes and side effects. It’s helpful to consider the pros and cons of using each product before deciding on one for your pool.

If your pool has a low pH and you need to increase the alkalinity, baking soda is a good way to go, as this will raise both of those levels in your pool. In fact, baking soda will affect the overall alkalinity even more than it raises the pH – the opposite effect of soda ash. So if both your pH and alkalinity need a boost, baking soda is your one-stop-shop.

However, baking soda comes with its own set of downsides. Adding too much baking soda can cause pH spikes, which will need some quick readjusting before there are significant negative impacts on your pool. In addition to turning your pool water cloudy, incorrectly adding baking soda (or adding too much baking soda) can cause difficult-to-remove stains and even lead to scaling problems.

For more information, read my full article on soda ash vs. baking soda.

How to Add Soda Ash to Your Pool

Before you start handling soda ash (or any chemicals) for your pool, it’s essential to wear your gloves and eye protection, as you don’t want pool cleaning chemicals coming into direct contact with your skin. You will also need a bucket and something to mix the chemicals with water– any kind of typical stirring stick should work.

Before you begin, you should also test the chemistry in your pool water to figure out exactly how much the pH levels and alkalinity need to be adjusted. You can accomplish this with test strips or, for greater accuracy, a liquid or digital testing kit. These are often more expensive but will give you the pH and alkaline levels to the decimal point, allowing you to be much more precise with the amount of soda ash you add.

Once you know how much soda ash you need, the next step is to collect some water from your pool in the bucket. You’ll need to read the soda ash product packaging carefully to determine the correct dosage required to achieve the pH balance you need for the size of the pool you have. Add the correct amount of soda ash to the water bucket and mix thoroughly. It’s essential to ensure that the soda ash is completely dissolved before it’s added to the pool. Otherwise, the chemicals may cause cloudiness.

Remember that the safest way to mix a solution, especially when working with potentially hazardous or corrosive materials, is to add the chemicals to the water and not the other way around. It’s never recommended to add water directly to the chemicals.

Generally speaking, for every six ounces of soda ash added to a 10,000-gallon pool, the pH level will increase by 0.2 while the alkalinity will rise by about 5 ppm. Use these measurements (and the instructions on the packaging) to determine how much soda ash you need to bring your pool’s pH levels between 7.4 and 7.6 based on the water volume. Keep in mind that clouding is likely to occur if you add over 16 ounces of soda ash per 10,000 gallons of water.

If you need to make more than one batch of the soda ash solution to ensure that your pool receives the right amount of chemicals, be sure to thoroughly dissolve every batch in water before adding it to your pool. It is safe to add the soda ash in multiple rounds, as long as the solution is spread evenly around the pool.

For an evenly distributed treatment, it’s helpful to carefully pour the solution around the perimeter of your pool. To maximize the soda ash spread around the pool, pouring the mixture in near the return jets for immediate circulation can be helpful. Take extra care to avoid the skimmer or any other filtration systems, as that will dilute the solution and significantly reduce the effectiveness of the treatment.

From here, we want to give the pool six hours to circulate the water and let the solution take effect. Then, it’s time to test the water chemistry and readjust as needed. If the water is still too acidic, you may need to add more soda ash– or a different pH adjustment method– to get it back into the correct range.

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What to Do if Your Pool Is Cloudy After Adding Soda Ash

Unfortunately, cloudiness is one of the main side effects of using soda ash to balance the pH pool, but it should only happen if the soda ash was added incorrectly or if the alkalinity reaches over 120 ppm. If the cloudiness is due to high alkaline levels, you can use muriatic acid to lower alkalinity.

Here are some tips for introducing soda ash into your pool that will help you reduce the after-treatment cloudiness:

  • Make sure that you completely dissolve the soda ash with water (as per the specific product instructions) before mixing it into the pool.
  • Don’t add the soda ash while you are also adding calcium chloride. The same is true when using baking soda. Different chemicals should be added separately or a reaction could occur.
  • Measure carefully to make sure you are adding the recommended amount of soda ash to get your pH to the right level. Adding too much soda ash will spike the alkalinity and require further rebalancing to fix.

These preventative measures should help your pool stay clean, clear, and balanced with its soda ash solution.

As always, frequently retest your pool water and adjust your chemicals to maintain the best clarity for safety and enjoyment. Whenever you discover that your pool’s acidity is too high, soda ash is a convenient and simple solution to get that water swim-worthy again.

Have questions? Drop me a line; always happy to lend a hand.

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