Pool owners often struggle when deciding whether to use soda ash or baking soda in their pool. While both are good options, their uses differ and it is important to know when to use each.
Soda ash is the best product for your pool water to make large pH adjustments and to adjust pH and alkalinity at the same time. Baking soda will minimally raise pH levels and is best used to raise alkalinity without overly affecting the pH levels.
It is impossible to raise pH without raising alkalinity and the other way around. Baking soda and soda ash both achieve similar things, but their uses are slightly different.
Read on to learn how and when to add each to your pool and the difference in cost between soda ash and baking soda.
Article Contents
What is Soda Ash?
Soda ash, also known as sodium carbonate, is pool chemical that has high alkalinity and a pH between 11.3- 11.7. The purpose of soda ash is to raise the pH in your pool while also raising your alkalinity levels.
When purchasing soda ash, it can be commonly named or label as “pH Increaser”.
The product here is soda ash aka sodium carbonate:
- For pool or spas
- Sodium bicarbonate - best choice to increase alkalinity
- Prevents potential skin irritations by keeping pH within ideal range
When to Use Soda Ash in your Pool
Soda ash should be used in your pool when you need to raise your pH levels and raise alkalinity at the same time. If you are needing to raise your pH, chances are that your alkalinity levels have fallen significantly as well.
- Raise pH AND Alkalinity
- Large pH changes
The desired alkalinity levels in your pool should be in the range of 80-150 ppm. If you have low alkalinity and a pH that isn’t between 7.2-7.6, soda ash is your best option, or if you simply need to raise your pH, soda ash will be used.
Soda ash will have a big effect on your pool’s pH level, much more than baking soda. As a result you need much less soda ash to raise your pH level when compared to baking soda.
If your pH is below desired range such as 7.0 and you have a pool that is 10,000 gallons, adding 12.2 ounces or 0.7 pounds of soda ash will bring the pH back to 7.4. This amount of soda ash needed will vary depending on the other chemical levels.
While boosting pH back up to a desired range, 12.2 ounces of soda ash will also raise the alkalinity levels by about 8.5 PPM.
To properly add soda ash into your pool, measure the amount needed and dump into a bucket of water. Be sure to stir the soda ash until it is fully dissolved to avoid cloudy water in your pool.
Once dissolved into a bucket, pour the solution into your pool as you walk around the perimeter. Avoid pouring near the filter because if the solution goes into the filter the filter will dilute it and make it useless.
Wait six hours before testing the chemical levels again.
Side Effects of Using Soda Ash
When adding any chemical to your pool, adding it improperly can cause unwanted effects on your pool chemistry.
It is important to know what your chemical levels are before adding any other chemicals to your pool. If soda ash is incorrectly added into your pool, cloudy water can result.
Cloudy water as a result of soda ash can be caused by not fully dissolving it into a bucket of water before adding it to the pool. Undissolved soda ash will sit in your water as there is not enough circulation to dissolve once its added it.
If soda ash and calcium chloride are added into your pool at the same time, your pool will become cloudy. This is caused by a chemical reaction. Remember to never mix chemicals in your pool and follow manufacturers directions when adding and storing chemicals.
If too much soda ash is added to the pool, the total alkalinity of your pool with rise to the point where there is cloudy water. When this happens, you will then have to add muriatic acid (hydrochloric acid) or sodium bisulfate to lower your alkalinity in your pool.
What is Baking Soda for your Pool?
You have been using baking soda your entire life, but did you know it can be used in your pool as well? That’s right, in fact, baking soda is one of the most common pool chemicals you can find.
Also known as sodium bicarbonate and bicarb soda, baking soda is used to raise the alkalinity levels of your pool water, while minimally raising your pH levels.
- Raise alkalinity
- Slightly raises pH
This product here is baking soda aka sodium bicarbonate:
- Keeps your pH and Chlorine stable
- Easier to apply to water
- Compatible with pool, spa, and hot tub
Baking soda has a pH of about 8 so it will raise pH only slightly. If a big adjustment is needed, it’s better to add soda ash.
Baking soda should be used in situations where you have low alkalinity levels, but you pH levels are in the desired range of 7.2-7.6.
As a side note, the pH scale is logarithmic. The difference between a pH of 7 and a pH of 8 is actually 10 times more basic (more alkaline).
How to use Baking Soda in your Pool
You use baking soda the same way you do soda ash. Baking soda will need to be mixed in a bucket of water before being added to your pool.
For a pool that is 10,000 gallons, if you are looking to raise your alkalinity levels by 10 ppm, you will need to add about 1.5 pounds of baking soda.
Keep in mind, this will minimally raise your pH as well, but if it does, you can use muriatic acid to bring it back down.
Again, you should avoid adding baking soda in front of your pool filter as the filter will dilute the chemical and it will not raise your pH or alkalinity as you hoped.
You should wait six hours before testing your chemicals again to give the baking soda time to settle in and give yourself an accurate measurement.
Side Effects of Using Baking Soda
Much like soda ash, if too much baking soda is added to your pool, your total alkalinity will get too high and lead to cloudy water. In addition, baking soda can also lead to high pH if a lot is used. A pH that is too high can lead to a number of issues that should be avoided.
High pH in your pool can lead to cloudy water, but it can also cause surfaces, such as liners, to become stained from the high levels. Secondly, high pH levels will lead to scaling issues in your pool.
Occurring most commonly at the water line, scaling of your pool is unsightly and will require additional chemical and or elbow grease to remove.
And most importantly, incorrect pH is not good for swimmers. It causes skin and eye irritation.
If your pH is raised too much as a result of baking soda, or any other chemical for that matter, it is best to use muriatic acid to bring your pH back to desired levels.
You can get muriatic acid here:
- Same powerful cleaning properties as muriatic acid, but with added benefits
- Reduces the risk of corrosive damage to surfaces
- Effective alternative to traditional muriatic acid
Does Baking Soda or Soda Ash Cost Less?
When looking at prices, soda ash is more expensive than baking soda per pound / kilo. Baking soda is a widely available product that has many uses.
In addition to being used in your pool, baking soda can also be used as a product that has many other benefits around the home like cleaning and baking. Baking soda can be bought at your local grocery store or any other store that sells cleaning products and can often be bought in bulk for a cheaper price.
Soda ash will cost about $15 for 5 pounds, whereas baking soda will cost almost half of that at only about $8 for a 5 pound bag. You can see the breakdown of net weight to price of each below.
Baking Soda Cost
| Net Weight | Price |
| 1 lb | <$1 |
| 5 lb | $5 |
| 12 lb | $10 |
| 50 lb | $55 |
Soda Ash Cost
| Net Weight | Price |
| 1 lb | $8 |
| 5 lb | $15 |
| 10 lb | $20 |
| 50 lb | $70 |
The cost of soda ash is clearly more than the cost of baking soda for any size that you purchase, in fact it’s more than double in some cases. The costs level out a little if you buy bulk though.
While soda ash is certainly more expensive per pound. That’s not the whole story. Remember that soda ash has a much bigger affect on pH. You’ll need 4-10 the quantity of baking soda to raise the pH when compared to soda ash.
Baking Soda Vs Soda Ash Cost
The table below demonstrates the costs of both baking soda and sodium soda ash to raise the pH level of a 10,000 gallon pool from a pH of 7.1 to 7.5. It assumes total alkalinity starts at 60 ppm and was raised to 100 ppm.
| Baking Soda (Sodium Bicarbonate) | Soda Ash (Sodium Carbonate) | |
| Cost (50 lb Bag) | Approx. $55 | Approx. $70 |
| Cost Per Pound | $1.10 | $1.40 |
| Amount Needed | 6 lbs (2.7 kg) | 15 oz (420g) |
| Real Cost to Adjust pH | $6.60 | $1.31 |
As you can see if you used baking soda to adjust the pH it would cost you 5 times as much. The difference would be even greater if you needed to raise the pH a lot more.
Should You Use Soda Ash or Baking Soda for your Pool?
Before you can decide if you should used soda ash or baking soda in your pool, it is important to understand the differences and similarities between the two.
Soda ash contains a pH of 11.3-11.7 while baking soda has a pH of only about 8. Because of this, baking soda won’t raise pH anywhere near as much as soda ash.
When looking to raise both pH and alkalinity, or raise the pH a lot, soda ash is the best choice . If you are looking to only raise the alkalinity in your pool while minimally raising your pH, baking soda is the best option.
pH levels and total alkalinity work hand in hand in your pool, that’s why it is important to know when to use which product.
Total alkalinity in the desired range of 80-150 will also keep pH in a desired range of 7.2-7.6. When either chemical balance is off, the other one will be effected as well.
When alkalinity is low, pH bounce can occur. This is when the pH of your pool can fluctuate drastically and can have impacts on your pool itself or your chlorine. Alkalinity buffers the pH and stops drastic movements in pH.
When needing to raise pH on a regular basis, soda ash should be used. You may initially use baking soda to correct alkalinity and pH if needed, but any other pH corrections should be accomplished with only soda ash.
Check out the chart below for the full breakdown.
| Product | Soda Ash (Sodium Carbonate) | Baking Soda (Sodium Bicarbonate) |
| Use | Raises pH substantially and raises alkalinity | Raises alkalinity & very slightly raises pH |
| pH | 11.3-11.7 | 8 |
| Side Effects | Cloudy water if not dissolved before adding. | If using to raise pH, alkalinity may be too high resulting in cloudy water. |
| Cost | Costs less as you need much less to do the same job. | Costs more as you need more. |
| Other Uses | N/A | Household Cleaning |
How to Lower Alkalinity and pH Levels
If you happen to add to much soda ash or baking soda, or you add the wrong product, you may realize that you need to lower your pH and alkalinity.
To do this, you will need to add sodium bisulphate or muriatic acid into your pool. Muriatic Acid is the most common product to lower alkalinity and pH.
With a 10,000 gallon pool, if your pH levels were 8 and you wanted to lower them, you should add 32-48 fluid ounces of muriatic acid. If your pH was 8.8 or higher you would add 55-87 fluid ounces of muriatic acid to your pool to return it to normal levels.
Be sure to safely add Muriatic Acid to you pool, as it is highly corrosive and dangerous if not handled properly.
Further Read: How to Lower the pH in your Pool
Final Thoughts
Both baking soda and soda ash are great options for use in your pool, however, their uses may vary depending on your chemical levels.
Use soda ash for when you want to raise both pH and alkalinity and use baking soda when you want to raise alkalinity without raising pH too much.
As with any chemical, make sure that you are reading manufacturers direction and never mix chemicals or store them too close together as dangerous chemical reactions can result.
Related Reading:
2 Ways to Raise pH in Hot Tub (pH is Low)
What To Do If You Add Too Much Muriatic Acid To Pool
Fix a Cloudy Pool After Adding Soda Ash (pH Increaser)
Neutralize And Clean Up A Muriatic Acid Spill (Around A Pool)
How to Lower Alkalinity in Pool Without Affecting pH
