Raising your pool’s alkalinity is a simple DIY project that only requires baking soda, your pool test kit, and a little patience. Read on for the exact calculations to determine how much baking soda you need, the best techniques for adding it to your pool, and what I do to keep my water crystal-clear and swim-ready.
Why bother? Because low alkalinity — below 80 ppm — can corrode equipment, destabilize pH levels, and damage your pool surfaces.
| Project difficulty: Easy Estimated time to complete: 30 minutes (plus 4-6 hours wait time) Project cost: $10 – $20 |
What is Alkalinity
Total alkalinity (TA) acts as your pool’s pH stabilizer. It prevents sudden changes that can result from stormy weather or after a pool party.
Your pool’s alkalinity should stay between 80-120 parts per million (ppm). Checking it at least once a week will help keep all your chemicals in range to keep pool water from becoming acidic, corroding your pool equipment, and going green.
Steps to Raise Alkalinity in Your Pool
Raising the alkalinity is the same for freshwater and saltwater pools. You just need regular baking soda (sodium bicarbonate) to raise alkalinity.
Step 1: Test Your Pool Water
I use test strips for quick checks but use a standard drop kit for more accurate readings. If alkalinity is below 80 ppm, the test solution stays green. For the easiest and most precise option, you can pick up a digital pool water tester.
Here in West Texas, I’ve found that you get the most accurate and consistent readings when you test the water in the morning before the sun hits it.
Step 2: Calculate Amount of Baking Soda Needed
Alkalinity Calculator
These days, I’m content with a smaller 5,000 gallon pool compared to the 18,000 gallon one my friend has, but regardless of the size, the process for raising the alkalinity levels is the same. Here's what you need to know for a typical 10,000-gallon pool.
The Basic Rule: 1.5 pounds of baking soda will raise alkalinity by 10 ppm in a 10,000-gallon pool.
To calculate how much you need:
- Figure out how many ppm you need to raise the alkalinity to between 80 and 120 ppm.
Example: Your test shows you alkaline level is 50 ppm, and your goal is 90 ppm, an increase of 40 ppm
- Divide your pool volume in gallons by 10,000
- Multiply by 1.5 lbs of baking soda
- Then, multiply by the desired ppm increase divided by 10.
Example - For a 15,000-gallon pool needing a 40 ppm increase, the calculation is:
15,000 ÷ 10,000 × 1.5 × (40 ÷ 10) = 9 lbs of baking soda.
My tip: I often buy large bags of baking soda at my local grocery or hardware store. It’s usually cheaper than branded “alkalinity increasers,” which are essentially the same product.
Step 3: Add the Baking Soda
Here’s how I do it:
Add 1/2 to 3/4 of your calculated baking soda amount by broadcasting it in wide arcs across the pool surface. Never add baking soda through the skimmer; it can damage your equipment.
Don’t just dump it in, as most of it will settle to the bottom. You can also dissolve it in a 5-gallon bucket half full of pool water, then pour it in slowly to let the jets circulate it.
Run your pool's filtration system for at least six hours to let the baking soda circulate and dissolve completely. I usually let it run overnight.
My tip: Mind the wind. A single gust at the right time can send your baking soda flying into the neighbor's yard, and unfortunately, right into their face if they happen to be on the other side of the fence. He didn’t think it was as funny as I did.
Step 4: Retest and Adjust if Needed
This is where your patience pays off.
Test both total alkalinity and pH levels using your liquid test kit or test strips after the circulation time.
Repeat the process with the remaining baking soda until you reach the desired levels, if needed. It’s much easier to add more baking soda later than to have to go back and try to rebalance it with an acid.
My tip: If I accidentally overshot (which has happened during "pool math" failures), I don't worry too much if it's just slightly high. I've found it's better to be at the higher end of the range (100-120 ppm) during summer, as the intense heat and evaporation tend to concentrate chemicals over time.
What Causes Low Alkalinity?
A few things can drop your total alkalinity levels, including low pH, heavy pool use, too much muriatic acid, heavy rain, and repeatedly shocking your pool.
Simon Spragg of Techpools explains the rain effect: "Surrounding vegetation can be the cause of 'acid rain' which will reduce pH. In other areas of the world, rain may be more alkaline.”
FAQ About Alkalinity in a Pool
When both are low, it's best to adjust the alkalinity first with baking soda (sodium bicarbonate) to bring it into range, then use soda ash (sodium carbonate) to bump up the pH if it’s still low. Going in the opposite order will leave your pH bouncing all over the place.
Technically, yes. By itself, alkalinity doesn’t make a pool unsafe to swim in. However, the side effects of high alkalinity can make the water less desirable. It can render chlorine’s sanitation power ineffective and the resulting high pH may cause skin rashes and eye irritation, depending on how extreme the levels are.
Baking soda (sodium bicarbonate) works to raise alkalinity while only slightly elevating pH levels. Soda ash (sodium carbonate) works to raise pH while only slightly elevating alkalinity.
Keeping the Balance
Being proactive about testing and adjusting alkalinity saves time and money in the long run. It prevents equipment damage, reduces the need for extra chemicals, and keeps your pool swim-ready all season long.
If you need a hand with your pool chemistry, Home Gnome delivers the best home service experience at the click of a button. Book reliable, skilled pool services and leave the rest to us.
Home Gnome delivers the best home service experience at the click of a button. Book reliable, skilled services in seconds and leave the rest to us.
Main Image Credit: strannik9211 / Adobe Stock
Related Posts:
