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Here’s a secret for pool owners. Some brands of alkalinity increaser have just one active ingredient: sodium bicarbonate. Well, guess what? Sodium bicarbonate is baking soda.
Baking soda raises alkalinity levels in your pool. AND it can be less expensive than Alkalinity Increaser.
Test your pool water daily. Your alkalinity levels should be between 100 and 150 ppm or parts per million. And increasing alkalinity affects pH, which should be between 7.4 and 7.6.
You can either have acidic water or basic pool water. The level of how acidic your pool water is is determined by the pH scale.
The lower the pH level, the more acidic your water will be. Acidic water can cause long-term damage to all your equipment and pool surfaces by eating away at it over time.
The higher the pH level, the more basic your water will be. Basic water can also cause damage by adding a layer of film (or scaling) to your pool parts. Do you know that white, crusty build-up you sometimes see on showerheads? That’s what can happen to your pool and all its equipment.
Here’s a visual of the pH scale. Pool water can be as low as 6 or as high as 8. Your goal is to keep it neutral. Which for a swimming pool is between 7.4 and 7.6.
Now, alkalinity is your pH buffer. But I like to call it pH’s bodyguard. Having the alkalinity of the water between 100 and 150 ppm (parts per million) will help keep a stable pH.
For example, every time it rains or when someone jumps in the pool, that can affect your pH. It can cause it to go up or down dramatically. But alkalinity will take the brunt of the hit before your pH does. And that’s why it’s important to use the right amount of baking soda to keep both your pH and alkalinity levels correct.
As a rule of thumb, use 1.5 pounds (680 grams) of baking soda per 10,000 gallons (37,854 liters) of pool water. This should raise the alkalinity by about 10ppm (parts per million). Or you can use the chart below.
If you’re not sure how much water your pool holds, check out our pool calculator.
Once you know your pool’s volume, and you’ve measured out the baking soda, don’t add it all at once! If you adjust the alkalinity too much in either direction, it can affect the pH as well.
Note: It doesn’t matter which type of baking soda you use. The most popular brand is Arm & Hammer, which is a good choice. Any grocery store brand will do as long as the main and only ingredient is Sodium Bicarbonate.
An affordable alternative to traditional chemicals, baking soda will naturally raise the alkalinity and pH in your water. It's also useful for cleaning tiles and surfaces.
Note: We don’t recommend adding baking soda directly into your skimmer. Adding chemicals through your filter system can be dangerous especially if you have a chlorinator or chemical feeder. It’s actually easier to just add it directly to the water.
If any of this is confusing so far, don’t worry. Pool chemistry can seem overwhelming, but it’s actually really easy if you just have the right education and some tools at your disposal. That’s why we created our own pool maintenance video course to teach you everything you need to know about chemistry, cleaning, and troubleshooting.
Baking Soda (Sodium Bicarbonate) is used to raise alkalinity and also slightly raise pH. And Soda Ash (Sodium Carbonate) is used to raise pH and slightly raise alkalinity.
For example, getting a pH reading around 7.2 to 7.6 in 10,000 gallons (37,854 liters) of pool water would take roughly 21 pounds of baking soda. This would also increase the Total Alkalinity by roughly 150 ppm (parts per million). And that’s way too much!
But if we wanted to increase the pH of the pool by 0.5, we could use roughly 12 ounces (340 grams) of soda ash. That would only increase the total alkalinity by roughly 8 ppm.
In other words, use baking soda to increase alkalinity and soda ash to increase pH.
No. But keeping your pH and alkalinity properly balanced helps maintain a stable chlorine level which helps kill pool algae and keep it out of the water. However, if you have a green pool, then you need to follow our detailed instructions on getting rid of pool algae and keep it from coming back. You can also try using an algaecide, too.
Not directly, but it can help. If your water is under-sanitized and causing cloudiness, then you want to make sure your pH and alkalinity are balanced before adding sanitizer.
That said, adding too much baking soda at once can cause your pool water to be cloudy. Usually, you just have to wait for it to fully dissolve, so don’t panic. High alkalinity can also cause cloudy water. Check out our guide to fixing cloudy pool water.
While there’s no risk in using baking soda in your pool, there are risks to having high and low alkalinity.
You might notice corrosion in and around your ladders, liner, tiles, or other parts of your pool. This is likely due to low pH and alkalinity for long periods of time.
And if you see scaling or a build-up around your pool equipment, this could be caused by high pH and alkalinity. And it means your water is hard.
All you have to do is keep the alkalinity between 100 and 150 ppm and the pH between 7.4 and 7.6 as often as possible. Test your pool water daily and adjust your chemical levels when needed.
We mentioned getting it in your eye if you add it to your pool on a windy day. That hurts like hell. But besides that, sodium bicarbonate (aka baking soda) is relatively safe.
Sodium bicarbonate has been used for thousands of years. Most notably by Ancient Egyptians who used it to clean their teeth. Just like we do today!
And it’s “Generally Recognized as Safe” by the FDA as a direct food additive.
Think of it this way, if it’s safe enough to use in cakes, then your swimming pool won’t be a problem.
The best part about all this is that baking soda is often cheaper than an alkalinity increaser. And you can buy baking soda in bulk just like the pool supply store brand.
On top of that, you can always use any extra baking soda to brush your teeth, make a cake, or clean your dishes.
Happy Swimming!
Matt is the founder of Swim University. He's been in the pool industry since 1993. His mission is to make pool care easy for everyone. Each year, he continues to help more people with water chemistry, cleaning, and troubleshooting.
A step-by-step guide on how to raise ph in your pool with three inexpensive solutions: Soda ash, baking soda, or pH increaser.
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