Soda Ash vs. Baking Soda: What’s the Difference?

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Soda Ash vs Baking Soda

A balanced pool should have a pH of between 7.4 and 7.6 and an alkalinity level of 80 to 120 ppm (parts per million). However, no matter how keen you are on the pool chemistry, fluctuations are inevitable.

Soda ash and baking soda are handy for keeping the pool alkalinity and pH at the recommended levels. However, the two are quite different compounds that will come in handy for varying situations. It is essential to know how they differ and when to use either.

Why We Use Soda Ash in Pool?

Soda ash for pools or sodium carbonate (Na2CO3) is typically used when you want to raise the pool’s pH. It is more effective for raising the pH because it is a highly alkaline compound with a pH level of 11.3 to 11.7.

Although some pool owners will also use it to alter the alkalinity levels, it has minimal effect, and you will need to use lots of it to get the levels you want. But, this is also an advantage as it means soda ash can be beneficial when you want to raise the pH without changing alkalinity.

The amount of soda ash you use determines how much you raise the pH. For example, if you have a 20,000-gallon swimming pool, adding around 12 ounces of soda ash should raise the pH level by at least 0.2 and the alkalinity levels by up to 5 ppm.

Read More: How to Use Soda Ash in Pool

Why We Use Baking Soda in Pool?

Baking soda or sodium bicarbonate (NaHCO3) is an alkaline compound, just like soda ash. However, it has a much lower pH level of around 8, meaning it will not raise pool pH levels significantly.

Adding baking soda to your pool has more effect on the alkalinity level than on the pH. Using it to raise the pH can be more problematic than helpful as you need to add lots of it. For example, it can cause the water to get cloudy and lead to scaling problems.

The right amount of baking soda for your pool depends on its size. For example, for a 20,000-gallon pool, you will need around 3 pounds of baking soda to raise the alkalinity level by 10 ppm.

Soda Ash vs. Baking Soda 

The main similarity between soda ash and baking soda is that both affect the pool’s pH and alkalinity. However, the effect level differs significantly. Soda ash will affect pH more than alkalinity, while baking soda has more effect on alkalinity than pH.

Another similarity is that adding both to your pool water requires mixing the compound with water before pouring it into the pool. You have to fill up a bucket with water from the pool and mix in the recommended amount of soda ash or baking powder.

The last step is to pour the mixture along the pool’s perimeter. It will take baking soda and soda ash at least 6 hours to disperse fully, after which you should test the alkalinity or pH levels again.

When it comes to the differences, the chemical composition and pH are the main ones. Soda ash (Na2CO3) has 2 atoms of sodium, 1 atom of carbon, 3 atoms of oxygen, and a pH level of 11.3 to 11.7. Baking soda (NaHCO3) has a pH of 8, and it will consist of 1 atom of sodium, 1 atom of hydrogen, 1 atom of carbon, and 3 atoms of oxygen.


Both soda ash and baking soda are highly useful compounds for maintaining pool water. But, given their different chemical composition and alkalinity levels, they will be ideal for varying purposes.

Soda ash has more effect on the pH levels and will be very useful when you want to raise the pool water’s pH. On the other hand, baking soda is your best bet for raising pool alkalinity levels.