To keep your pool water and equipment in top shape there are quite a few different levels you'll need to adjust. One of these is the pool "alkalinity" - which is a measure of dissolved alkaline substances in your water. Alkalinity tells us the water's ability to neutralize acid and closely tied to your pool's pH.
Baking Soda is Sodium Bicarbonate
If your pool water alkalinity is lower than it should be, one way to increase it is to go to your local pool supply store and pick up a bottle of "alkalinity increaser." But did you know alkalinity increaser is just sodium bicarbonate?
If that term sounds familiar, it's because sodium bicarbonate is also known as baking soda.
That's right. Simple baking soda. And chances are, you can buy baking soda for quite a bit less money than what you'd spend on "alkalinity increaser."
So next time you're out grocery shopping, swing by the baking aisle and check out the prices on bulk baking soda. If there's a big sale going on, be sure to stock up! You'll get all the same benefits of a packaged "alkalinity increaser" at a reduced cost.
How much baking soda should I use?
One of the potential drawbacks of using baking soda instead of a specially-packaged alkalinity increaser is that baking soda doesn't come with pool use instructions. But don't let that stop you from using it.
To calculate how much baking soda you should add, first determine the amount of gallons of water in your pool. Then add 1.5 pounds of baking soda for every 10,000 gallons of water to increase the pool's total alkalinity by 10 ppm.
For example: If your pool holds 20,000 gallons of water and your test kit is showing you a total alkalinity of 50 ppm, you will want to raise your alkalinity a minimum of 30 ppm (recommended alkalinity levels are generally in the 80-120 ppm range). Since the pool in this example is 20,000 gallons, every three pounds of baking soda should raise alkalinity roughly 10 ppm, which is only a third of the level you need. This means you will need to add roughly nine pounds of baking soda to a 20,000 gallon pool to raise the alkalinity by 30 ppm and achieve the minimum alkalinity goal of 80 ppm.
Add the baking soda directly to the pool, let it dissolve and give it time to distribute through your pool's water (at minimum 20 minutes with your pump running), test, and add more baking soda if needed.
Baking Soda and pH Levels
Adding baking soda will also raise your pool's pH level some, but if your main goal is to raise the pH versus simply raising alkalinity, we recommend using soda ash (available at most pool supply stores) in lieu of baking soda. Adding six ounces of soda ash (sodium carbonate) to 10,000 gallons of water will raise the pH roughly 0.2, while adding the same amount of baking soda (sodium bicarbonate) will have a negligible effect on your pH.
Note that soda ash does also raise alkalinity along with pH. That six ounces of soda ash will raise your alkalinity by about 5 ppm, so only use soda ash if you want to raise alkalinity and pH.
Soda Ash or Baking Soda?
- If you want to raise your pH and alkalinity together, use soda ash (sodium carbonate).
- If your goal is to raise alkalinity only, use baking soda (sodium bicarbonate).
With either solution, add in controlled doses. Test, add and adjust as needed. Too much of either and you risk throwing off your pool levels.
Always Keep Your Water Chemistry Balanced
As with any chemicals you may add to your pool, your main goal should be to keep the pool's water chemistry balanced. Test your water regularly and make adjustments as needed. You'll find that a balanced pool is not only prettier and requires less cleaning, but is also an absolute joy to swim and relax in.