Baking Soda Pool Calculator - How Much To Add To Lift Alkalinity?

Planning on adjusting your swimming pool or spa alkalinity with baking soda (sodium bicarbonate)? Find out exactly how much you need to dose with this handy baking soda pool calculator!

Why Use Baking Soda To Raise Alkalinity?

Alkalinity is an important part of your pool chemistry because it buffers your pH, preventing it from swinging wildly in reaction to minor disturbances in water quality.

Low alkalinity and the low pH that tends to come with it can bring a whole host of problems, including corrosion of your pool equipment and issues with chlorine effectiveness.

You can read more about these issues in this guide to low alkalinity in your pool.

Thankfully, baking soda is a cheap and effective way to lift your alkalinity.

What Is The Ideal Range For Pool Alkalinity?

It is generally recommended that you keep your pool alkalinity within 80 - 120 ppm (mg/L). However, deviations down to as low as 60 ppm or as high as 150 ppm are fine as long as your pool pH is stable.

Will Adding Sodium Bicarbonate Affect My pH?

Thankfully, baking soda has minimal impact on your pool water pH. That's because it has a natural pH of about 8.3, which is only slightly higher than the pH of your pool.

Depending on how much you use, you will see a small increase in pH after adding the sodium bicarbonate and giving it time to dissolve.

If you need to increase both alkalinity and pH, consider using soda ash (sodium carbonate). This chemical is closely related to baking soda, but is cheaper and has impacts both pH and alkalinity.

How Do I Calculate My Baking Soda Dose?

To begin with, enter your pool's volume in the calculator above. If you don't know your pool's volume, you can use this pool volume calculator to work it out.

Next, enter your current alkalinity level (in mg/L or ppm - they are equivalent). If you don't know this, you can use any decent pool test kit or testing strips to find out. Follow the product instructions to ensure you get an accurate measurement.

Finally, enter your desired alkalinity level (again, in mg/L or ppm), bearing in mind that a level of 80 - 120 ppm is generally recommended.

How Much Sodium Bicarbonate Should I Add To My Pool?

As an example, for a 50,000 L pool with a current alkalinity level of 40 ppm and a desired alkalinity level of 100 ppm, you would need to add 4.1 kg of baking soda (sodium bicarbonate).

Can I Add Too Much Baking Soda?

Yes. Excess alkalinty can be a problem. If you accidentally dose too much baking soda, you run the risk of metal staining and calcium scaling on your pool surface.

If not managed appropriately, you may damage your pool equipment (pump, filter housing, skimmer basket) as well as plastic and rubber pool toys and goggles.

For more information, as well as how to fix this problem, check out this guide to high alkalinity in your pool.