Soda Ash Vs Baking Soda For Pools (When To Use Which)



Fluctuations in your pool’s water chemistry are unavoidable, but they’re easily treatable if you understand how all the chemicals interact with each other.

When the pool’s pH level and total alkalinity get out of whack, both soda ash and baking soda can be used to bring it back into balance. 

But which is better for your pool? The soda ash vs baking soda debate is broken down below.

What Is A “Balanced” Pool?

A balanced pool has a pH level of between 7.4 and 7.6. Higher than 7.6 will cause the water to become too alkaline (basic), and a lower than 7.4 will turn it acidic.

It also has a total alkalinity reading of between 80 and 120 parts per million (ppm). Keeping the alkalinity in its proper range helps stabilize the pH so it doesn’t wildly deviate.

Both soda ash and baking soda are used to restore balance, but one isn’t always better than the other.

Why Use Soda Ash In A Pool?

Soda ash (sodium carbonate) is a highly alkaline substance with a pH level between 11.3 and 11.7 – making it an ideal substance for raising the pool’s pH and total alkalinity.

Soda ash minimally raises the alkalinity level, so if you have a pool that needs a pH bump without also jacking up total alkalinity (because it’s already in the proper range), soda ash is a great choice.

In terms of numbers, 6 ounces of soda ash in a 10,000 gallon pool will raise the pH level by 0.2 with total alkalinity increased by only 5 ppm.

Side Effects Of Using Soda Ash

Soda ash is safe for your pool, but you may experience cloudy water if it’s added improperly.

This can happen if:

  • You don’t fully dissolve the soda ash with water before adding it to the pool.
  • You add too much soda ash, spiking the total alkalinity (which means you’ll then have to lower it)
  • You add soda ash at the same time as calcium chloride

Adding Soda Ash To A Pool

Adding soda ash to your pool and only requires you use a bucket, and wear protective goggles and gloves.

Start by filling up the bucket by scooping out water from your pool. After measuring the correct dosage of soda ash you’ll need, pour it into the bucket of water. Stir it up until the soda ash is dissolved (a paint stir stick works well).

Then, walk around the perimeter of the pool and pour the solution into the water. Be careful not to add it near the skimmer. Doing so will send the solution through the pool system and the filter will dilute it.

Let the pool circulate the water for 6 hours before testing again. Adjust chemical levels if needed.

Why Use Baking Soda In A Pool?

Baking soda (sodium bicarbonate) is also an alkaline substance, but with a lower pH level of 8 – commonly used to increase pH and total alkalinity. In fact, most pH Increaser products are just baking soda in a fancy bottle! 

Using baking soda will affect the pool’s total alkalinity more than the pH.

In general, adding 1.5 lbs of baking soda to a 10,000 gallon pool will raise the alkalinity by 10 ppm. It’s also quite common to have to dose the pool with over 5 lbs. of baking soda just to bring the pH level back into its proper range.

Side Effects Of Using Baking Soda

Baking soda can cause issues if you add too much of it to the water, causing the pH level to spike.

High pH water can:

If that happens, you’ll have to add muriatic acid to bring the pH level down.

Adding Baking Soda To A Pool

Baking soda is easy to add to the pool and can be poured straight into the pool after mixing it with water. 

We’d recommend not doing this on a windy day (for obvious reasons), and you’ll have to test the water first so you can calculate how much baking soda is needed.

Also, adding baking soda in front of the return jets will distribute it faster, but you should still wait 6 hours for it to fully disperse. After this time, retest the pool and add more if needed.

Summary: Soda Ash Vs Baking Soda

Soda ash and baking soda can both be used to raise a pool’s pH and total alkalinity levels, but they work in opposite ways.

Soda ash will raise pH and minimally raise alkalinity, while baking soda will raise alkalinity and minimally raise pH. 

Use baking soda when the pH isn’t off by much, but the alkalinity is way too low, and use soda ash when the pH needs to be drastically increased but you want the alkalinity to be less affected.

What About Borax?

Borax (sodium borate) is another powdery mineral that can be used to raise the pH level of your pool water. However, what it won’t do is affect the water’s alkalinity levels, which both soda ash and baking soda raise along with pH.

Borax is a pH buffer, protecting the water’s pH level from heavy fluctuations. This ensures your chlorine levels won’t drop too quickly, protecting your pool from an algae bloom.

Borax also stays in your pool and works for a long time, whereas soda ash and baking soda quickly evaporate once they’ve raised the pH level. With borax hanging around, the water will stay softer, chloramines will take less time to form, and you’ll also use less chlorine.

The main drawback of using borax is that it has a high pH level of 9.5, which will raise the pool’s pH pretty fast when added in large amounts. In order to lower the pH level, you’ll have to add a pH reducer to the water such as muriatic acid.

Both Are Useful!

In short, you can use either soda ash or baking soda to raise your pH level, but they will affect the pool water in slightly different ways.

Knowing which one to add will keep the water properly balanced.

Categories: Pool Care, Pool Chemistry