Soda Ash or Baking Soda: Which One Is Better for a Pool?

In many areas of the country, pools provide a common place of fun during the warmer months of summer. Keeping pools clean and chemically balanced is a critical aspect of their maintenance.

Soda ash and baking soda are two chemicals used to regulate pool chemistry.  Neither is better than the other. It depends on what one wants to do. Soda ash is used to increase the pool’s pH while baking soda is used to increase the pool’s alkalinity.

What’s the difference? We’ll discuss that and more below.


Can I Use Baking Soda Instead of Soda Ash in My Pool?

Whether or not one can use baking soda instead of soda ash in a pool depends entirely upon what one wants to accomplish. 

If you are trying to increase the pH of the pool water then the product to use is soda ash. On the other hand, if one wants to increase the alkalinity of the pool water then the product to use is baking soda.

Although both increase both aspects of a pool’s chemistry, they increase them at different rates. Soda ash increases pH more quickly than it does alkalinity. Baking soda, on the other hand, increases alkalinity more quickly than it does pH.

What Is Considered a Balanced Pool?

Let’s start at the beginning. A pool’s water chemistry tends to fluctuate over time. As a result, the owner may need to adjust its pH levels or its alkalinity using either soda ash or baking soda.

The ideal levels for a balanced pool will vary somewhat depending upon which expert one asks. Generally, the minimum permissible pH of a pool will range between 7.2 and 7.4. The maximum permissible pH of a pool will range between 7.6 and 7.8.

If one remembers one’s high school chemistry, pH is a measure of the acidity of a solution. It depends on the concentration of hydrogen ions in the solution. Numerically, it can range from 0 to 14. Everything below 7 is considered acidic. Everything above 7 is considered basic. And 7.0 is neutral.

The above pH ranges for swimming pools are considered slightly basic. 

The alkalinity of a solution, in this context, is a measure of the pool water to resist acidification. It is measured in parts per million (ppm). Generally, the alkalinity of pool water should range somewhere in the neighborhood of 80 to 120 ppm. The alkalinity range is useful in keeping the pH stabilized so it does not suffer from wide erratic swings.

The idea for swimming pools is to maintain a pH that serves as some kind of disinfectant (because many people and their germs will be swimming in it). It needs to be strong enough to kill germs without damaging the skin or eyes.

Health Problems from Unbalanced Pools

Failure to maintain a proper pH and alkalinity level in pool water can lead to certain nuisance health problems. The most common such problems are:

  • Brittle hair
  • Dry skin
  • Eye irritation

So, it’s a good idea to keep a pool properly maintained.

Which Should I Use for My Pool: Baking Soda or Soda Ash?

As should be apparent from the discussion above, baking soda and soda ash are not interchangeable. They are used to serve different ends. Baking soda is used to increase alkalinity. Basically, it serves to stabilize the pH of the pool water and keep it from changing too much.

Soda ash is used to increase the actual pH. If one finds that the pH of one’s pool water has dropped too low, soda ash is the chemical recommended to solve the problem.

As a result, it is inadvisable to use baking soda instead of soda ash. Each has its preferred use.

Soda Ash Is Sodium Carbonate

Is Soda Ash Good for Pools?

Soda ash is the chemical compound one should use to increase the pH of the water in a pool. Chemically speaking, soda ash is known as sodium bicarbonate. On its own, it has a pH ranging between 11.3 and 11.7. This is dramatically higher than the mere 8 of baking soda.

Because of that, it is the preferred substance to be used to raise a pool’s pH. So, yes, it is perfectly good for pools—if the goal is to raise the pH. For example, one can raise the pH level of a 10,000 gallon pool by as much as 0.2 using only 6 ounces of soda ash. At the same time, this will only increase the total alkalinity by 5 ppm.

Soda ash is perfectly safe for pools when used properly (But see below for instructions how). 

When Should I Use Soda Ash in My Pool?

Soda ash should be used when one is concerned with only the pH of the water. As stated above, soda ash is an excellent choice for raising pH levels.

If one is concerned with alkalinity, one may wish to use baking soda instead. If concerned with both, perhaps a combination of the two may be needed.

How Do You Add Soda Ash to Pool Water?

The first thing to be aware of about soda ash is that it is highly basic and bases can be as damaging to human flesh as acids. Because of this, one should always use protective gloves and goggles when adding soda ash to one’s pool. 

So, when adding soda ash to pool water follow these steps:

  • Wear protective gloves and goggles (Reminder)
  • Fill a bucket with water from the pool.
  • Measure out the soda ash (use 6 oz. soda ash per 10,000 gallons and +0.2 pH)
  • Stir mixture together with paint stick or other stirring rod.
  • Pour the solution into the pool (don’t pour it near the skimmer as it will dilute the solution: the return jets make a good choice of location).
  • Wait six hours for it to properly distribute throughout the pool.
  • Recheck the appropriate chemical levels (pH and alkalinity).
  • Repeat as needed.

There are a couple further points to keep in mind when adding soda ash to one’s pool if one wants to avoid the unwelcome side effect of cloudy water.

  • Don’t add too much soda ash to the pool water as that may cause a spike in the pH.
  • Make sure to fully dissolve the soda ash in water before adding it to the pool.
  • Don’t add soda ash and calcium chloride at the same time.

If one keeps those points in mind, the process of adding soda ash should go fine.

What Can I Substitute for Soda Ash?

One possible substitute for soda ash is Borax, a chemical also known as sodium borate. Like soda ash it is more effective at raising pH levels than baking soda. Unlike both soda ash and baking soda, Borax doesn’t raise alkalinity.

It does serve as a pH buffer, though, keeping it from fluctuating too much. This protects the chlorine levels from dropping thereby preventing algae blooms. It also stays in the pool longer than the other mentioned chemicals. This will keep the water softer and reduce the amount of chlorine used over time.

What Does Baking Soda Do for Pools?

As we said, baking soda is used to increase the alkalinity of pool water. The ideal alkalinity of pool water is in the range of 80 ppm to 120 ppm. The ideal pH is between 7.2 and 7.8. Keeping both the alkalinity and the pH of the pool water in the proper range has a number of positive effects.

First, there are several important health effects which we’ve already mentioned above (prevents dry skin, etc…). Additionally, it is good for the actual physical pool by preventing corrosion of the pool tiles and keeping other various pool fixtures from deteriorating. 

Basically, if baking soda and soda ash are used to maintain proper pH and alkalinity levels, the pool will maintain its physical condition longer. Additionally, users of the pool will not suffer ill effects from the water.

What’s the Difference Between Baking Soda and Soda Ash?

Baking soda and soda ash are sometimes confused because they serve similar (although different) purposes. When added to a pool, each one will raise both the pool’s pH as well as the pool’s total alkalinity levels. What differs in each case is the degree to which each one raises each factor.

Baking soda is more effective at raising the alkalinity of a pool. It will also raise the pH, but not by much. Soda ash is just the reverse. Soda ash is very effective at raising the pH of a pool. It will also raise the alkalinity of a pool, just not by much.

This is all a result of the differing pH levels of the two products. Baking soda has a pH of around 8 while soda ash has a pH of around 11.3 to 11.7. That might not sound like a big difference (a little more than 3 points), but it is. The pH scale only goes up to 14 and it is logarithmic in nature. That means that a difference of 1 indicates a difference of 10 times.

So, following that rate of change the difference between 8 and 9 is 10 times, the difference between 9 and 10 is 10 times, and the difference between 10 and 11 is another 10 times. As a result, the difference between 8 and 11 on the pH scale is about 1000 times. So soda ash is far more potent than baking soda on the pH scale (1000+ times).

A Brief Look at Costs and Chemistry:

Generally speaking, a 50-lb bag of sodium bicarbonate (baking soda) will usually cost a little less than a 50-lb bag of sodium carbonate (soda ash). Precise numbers really aren’t useful here because prices change over time and in different locations—and Internet posts are available to the whole world for the rest of time.

Nevertheless, what won’t change is the chemistry involved in altering the pH and alkalinity of pool water. Due to the pH difference between soda ash and baking soda, soda ash is far more effective at altering pH levels (and baking soda is more effective at altering alkalinity levels).

If one wishes to alter the pH of a pool using baking soda, it can be done. It just takes a far larger amount of baking soda than it would soda ash.  At the same time, it may throw the alkalinity of the pool out of whack. Assuming it does not, an individual can probably get away with this on their own household pool.

However, if the individual is maintaining pools for a business, using baking soda to alter pH is strongly discouraged. Although safer (baking soda does not require gloves or goggles), it will rack up enormous extra expenses over time. Sometimes in the range of several thousand dollars a year, if not more.

Businesses can’t afford to throw that kind of money away. And, of course, the reverse argument applies to using soda ash to alter alkalinity.

Ultimately, from a financial perspective, our original point stands. Soda ash should be used to alter pH while baking soda should be used to alter alkalinity.

How Do You Add Baking Soda to a Pool?

Adding baking soda to a pool is much easier than adding soda ash because it isn’t really dangerous in any way. Here are the steps to follow:

  • Test the water and calculate how much baking soda is required.
  • Fill a bucket with pool water and pour the baking soda in the bucket.
  • Pour the mixture directly in the pool (near the return the jets is a good location).
  • Wait six hours for the chemicals to properly distribute.
  • Retest the chemical levels in the water.
  • Repeat as needed.

As can be seen, the process is fairly simple and straightforward and there is no danger from the baking soda (unlike soda ash). 


To sum up, pool water needs to be maintained at a pH of 7.2 to 7.8 and an alkalinity of 80 to 120 ppm. Both soda ash and baking soda can be used to raise either one of those values. However, soda ash is much more effective at raising the pH while baking soda is much more effective at raising the alkalinity. Use that information wisely and well.

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