How To Use Soda Ash Or Sodium Carbonate In Your Pool (Correctly)



Keeping your swimming pool in tip-top shape doesn’t just mean making it look good.

A whole bunch of chemicals go into the pool water to ensure it’s clean enough for swimming. At times, this balance of chemicals can be thrown out of whack, and you’ll have to fix it.

When the water is too acidic, adding soda ash to your pool will help. Let’s discuss why that is, and how to use it properly.

Why Use Soda Ash In A Pool?

When pool water is contaminated with pollutants from swimmers and the outside environment, chlorine in your pool becomes increasingly less effective.

This lack of sanitizing power causes the pool’s pH and total alkalinity levels to drop, causing the water to become too acidic. Raising those levels is necessary to restore the pool water to a neutral state.

Soda ash can do just that. Also known as sodium carbonate, it raises both the pH level and total alkalinity of the pool when added to the water.

Note: The ideal pH level for a pool is between 7.4 and 7.6. Anything over this number and the water is too alkaline (or basic), while anything under is too acidic. Total alkalinity of pool water should be between 80 and 120 ppm.

Soda Ash Vs Baking Soda

Isn’t soda ash the same as baking soda? Well, not quite – but they do have a lot in common.

Both baking soda (sodium bicarbonate), and soda ash (sodium carbonate) are highly alkaline substances, which makes them ideal for balancing acidic pool water. The difference is, while soda ash has a higher pH level, it also has less of an impact on total alkalinity.

At the right levels, alkalinity acts as a buffer to protect the pH level from wild fluctuations. When total alkalinity is too high, however, it impairs chlorine’s sanitizing ability, and can even make your pool water cloudy.

Ultimately, soda ash is a better choice if you’re aiming to raise the pool’s pH level while minimally raising total alkalinity, whereas baking soda is better for significantly raising both.

How To Add Soda Ash To Your Pool (Correctly)

Like most things when it comes to pool chemistry, there’s a right way and a wrong way to add substances to your water. Here are the steps you should follow to correctly raise your pH using soda ash:

Step 1. Test Your Pool Water

Start off by testing your pool water so you know where the pH and total alkalinity levels are currently at. 

There are a few different ways you can test your pool water. The most popular are test strips, which are dipped into a sample of pool water for a quick and fairly accurate reading.

If you want more precision, invest in a liquid testing kit or even a digital test kit. This will provide you with accuracy to the decimal point, so you know exactly how much soda ash you’ll need to add.

Step 2. Calculate The Dosage

As a general rule, around 6 ounces of soda ash in a 10,000 gallon pool will raise the pH level by 0.2 and the total alkalinity by 5 ppm.

To calculate the correct dosage, determine how much you need to raise the pH level of the water in order for it to be between 7.4 and 7.6, then figure out the volume of your pool water.

For example:

  • 7.2 to 7.4 in a 10,000 gallon pool = add 6 ounces of soda ash
  • 7.2 to 7.4 in a 20,000 gallon pool = add 12 ounces of soda ash
  • 7.0 to 7.4 in a 20,000 gallon pool = add 24 ounces of soda ash

Depending on how much you need to raise the pH level, you may need to add soda ash in multiple rounds.

Important: Adding more than 16 ounces (1 pound) per 10,000 gallons of water will  risk clouding up your pool, so be conservative when adding it.

Step 3. Suit Up And Make A Solution

While soda ash is pretty safe to handle, we still recommend suiting up in the appropriate attire – including rubber gloves and footwear, protective eyewear, long sleeves, and pants.

Now it’s time to make a solution to dilute the soda ash.

Dip a 5 gallon plastic bucket into the pool, filling it up halfway. Then, add the measured amount of soda ash to the water and stir it with a wooden stir stick until it’s fully dissolved.

Never add water to chemicals, always add chemicals to water. This is the safest way to create a solution.

Step 4. Pour It in

Once the soda ash is fully dissolved, you can add it to the pool. Be sure it’s fully dissolved, otherwise it may cause clouding of the pool water.

Now walk around the perimeter of the pool and slowly pour it in, aiming as close to the return jets as possible to help distribute it more evenly throughout your swimming pool.

Don’t pour it in front of the skimmer though, or it will be sucked into the filtration system and rendered useless.

Step 5. Retest And Adjust

Once any chemicals are added you should wait around 6 hours for the pool (your filter system) to fully distribute them in the water.

Afterwards, you can retest the pool water and add more soda ash if it’s needed.

Cloudy Pool After Adding Soda Ash?

As mentioned, adding soda ash can sometimes result in a cloudy pool.

This is usually due to the alkalinity level spiking over 120ppm. If this is the case, you’ll have to take measures to lower the pool’s alkalinity, in turn lowering the PH as well.

Additionally, adding calcium to your pool (like calcium chloride) at the same time as either soda ash OR baking soda can cause a reaction between the chemicals that will cloud up the pool. 

Finally, if your soda ash solution hasn’t been fully diluted before being poured into the pool, that might also be the culprit.

Balance Restored!

A swimming pool that’s gone haywire isn’t a life sentence, and restoring the pH level using soda ash in the pool is simple to do. 

Follow our steps and you’ll be back in the pool in no time.

Categories: Pool Care, Pool Chemistry