Pool Alkalinity

Understand Pool Alkalinity & Swimming Pool pH. Use A Swimming Pool Test Kit, Pool Acid & Baking Soda.

Swimming pool maintenance tips and spa chemistry for your inground and above ground pool maintenance.

More Questions ~ TA Charts

Easily Test & Adjust Your Total Alkalinity

How To Test Alkalinity

How To Raise Alkalnity

Remember to take small steps that when making adjustments to your (TA).

You can always add more but it's a little harder to get it out.

To raise the TA for pool maintenance, I recommend sodium bicarbonate (baking soda).

If you need lower your TA by a wide margin you'll want to do it in increments, not all at once.

How To Raise/Increase Your Pool Alkalinity

With the pool pump OFF and the water motionless:

  • Stand in one spot and slowly pour, don’t dump, the sodium bicarbonate into the deepest part of the pool. Sprinkle the Bicarbonate at you would use a salt shaker.  Wait at least 2-3 hours for pools and 1 hour for your Hot Tub or spa.
  • Turn the pump back on and allow the pool to cycle for about 8 - 10 hours, or a complete turn-over of the pool water, and 45 minutes for the Hot Tub or spa then re-test the total alkalinity.
  • Make another adjustment if necessary using the above technique. Remember, patience is a virtue when adjusting pool chemicals.

This will raise the total alkalinity but take care in monitoring your swimming pool pH because sodium bicarbonate affects both the pool alkalinity and your swimming pool pH level.


You've watched the above videos. Total alkalinity is just one aspect of pool maintenance. Now it's time to get all you need. Click on the picture above to get started down the road of having a perfect pool. Or better yet. Get your Instant Download!! 


Remember, this may take a few applications but you should reach the proper level. Refer to the chart to see how much sodium bicarb your pool needs.

When filling a pool, first test the total alkalinity of the fill water so you can have a good starting point. You can use pool test strips but I recommend an FAS-DPD K-2006 Taylor swimming pool test kit.

pool alkalinity, backing soda, sodium hydrogen carbonate, langelier index, alkalinity increaser, swimming pool care, basic pool care, inground pool maintenance

Decrease Your Pool Alkalinity

To lower pool alkalinity, either use muriatic acid (pool acid) or dry acid. Lowering the pool alkalinity may take a few applications, so patience is a virtue.

  • Add your pool acid, liquid or dry, standing in one spot using small circular motions to the deepest part of the pool with the filter off and the water motionless. Muriatic acid should be added a little at a time, diluting it prior to adding to the pool.
  • Allow the pool acid to do its job in lowering the alkalinity by keeping the pump motor off for at least 2-3 hours for pools and 1 hour for Hot Tubs.
  • Turn the pump motor back on and allow 8 - 10 hours for filtration, then re-test. Make another adjustment if you need by simply following this technique.

Another technique that works is a process called aeration, or "out-gassing". This technique requires you to add acid to lower both the TA and pH. then you introduce air into the pool via an air compressor, slides, waterfalls, water features, or perhaps a Shop Vac.

Pool Alkalinity

This creates millions of tiny bubbles which release their CO2 (carbon dioxide) and raises the pH while keeping the TA relatively lower. 

If you're thinking about lowering the total alkalinity by partially draining the pool and diluting your swimming pool water, you may want to think this through.

I would say only under extreme conditions should you do this. Not only will it take longer than using muriatic acid, but you'll waste alot of water. And if it doesn't work, you'll have to start all over again and probably use more pool chlorine than necessary.


Always take the proper precaution by wearing heavy duty rubber gloves and goggles. Or if you prefer, you may use dry acid. This is much easier and safer than liquid acid.

Contact one of your local pool cleaning services your pool alkalinity problem persists.

Remember when using pool acid and pool chlorine, safety should be your highest concern. Wearing heavy rubber gloves and goggles will minimize risk of injury.

Keep in mind, proper balance of your pool’s chlorine, swimming pool pH, pool alkalinity, and calcium hardness increaser is of the utmost importance in having a safe body of water. 

You’ll also get less headaches, spend less money and time worrying, and not want to drain the pool water. This will work even with a direct source of contaminated well water, your salt water pool system and salt cells.

Alkalinity Weekly Pool Maintenance Chart

Raise Pool Alkalinity 10ppm 40oz. (2 ½ pounds) of Sodium Bicarbonate (pump motor off and water motionless)
Lower Pool Alkalinity 10ppm ¼-½ gallon of acid or 8oz. of dry acid in one spot in the deep end (pump motor off and water motionless)

20,000 Gallon Pool
Raise Alkalinity 10ppm 2.5oz. of Sodium Bicarbonate (pump motor and jets off)
Lower Alkalinity 10ppm 6oz. acid (pump motor and jets off)

500 Gallon Hot Tub

Chart - Lowering Total Alkalinity Using Muriatic Acid

(ppm) 1,000 5,000 10,000 15,000 20,000 25,000 50,000
10 2.56 oz. 0.8 pts. 0.8 qts. 1.2 qts. 1.6 qts. 2.0 qts. 1 gal.
20 5.12 oz. 1.60 pts. 1.6 qts. 2.4 qts. 3.2 qts. 1.0 gal. 2 gal.
30 7.68 oz. 1.2 qts. 2.4 qts. 3.6 qts. 1.2 gal. 1.5 gal. 3 gal.
40 10.24 oz. 1.6 qts. 3.2 qts. 1.2 gal. 1.6 gal. 2.0 gal. 4 gal.
50 12.80 oz. 2.0 qts. 1.0 gal. 1.5 gal. 2.0 gal. 2.5 gal. 5 gal.
60 15.36 oz. 2.4 qts. 1.2 gal. 1.8 gal. 2.4 gal. 3.0 gal. 6 gal.
70 1.12 pts. 2.8 qts. 1.4 gal. 2.1 gal. 2.8 gal. 3.5 gal. 7 gal.
80 1.28 pts. 3.2 qts. 1.6 gal. 2.4 gal. 3.2 gal. 4.0 gal. 8 gal.
90 1.44 pts. 3.6 qts. 1.8 gal. 2.7 gal. 3.6 gal. 4.5 gal. 9 gal.
100 1.60 pts. 1.0 gal. 2.0 gal. 3.0 gal. 4.0 gal. 5.0 gal. 10 gal.

Chart - Raising Total Alkalinity Using Sodium Bicarbonate (Baking Soda)

(ppm) 1,000 5,000 10,000 15,000 20,000 25,000 50,000
10 0.14 lbs 0.7 lbs. 1.4 lbs. 2.1 lbs. 2.8 lbs. 3.5 lbs. 7 lbs.
20 0.28 lbs. 1.4 lbs. 2.8 lbs. 4.2 lbs. 5.6 lbs. 7.0 lbs. 14 lbs.
30 0.42 lbs. 2.1 lbs. 4.2 lbs. 6.3 lbs. 8.4 lbs. 10.5 lbs. 21 lbs.
40 0.56 lbs. 2.8 lbs. 5.6 lbs. 8.4 lbs. 11.2 lbs. 14.0 lbs. 28 lbs.
50 0.70 lbs. 3.5 lbs. 7 lbs. 10.5 lbs 14.0 lbs. 17.5 lbs. 35 lbs.
60 0.84 lbs. 4.2 lbs. 8.4 lbs. 12.6 lbs. 16.8 lbs. 21.0 lbs. 42 lbs.
70 0.98 lbs. 4.9 lbs. 9.8 lbs. 14.7 lbs. 19.6 lbs. 24.5 lbs. 49 lbs.
80 1.12 lbs. 5.6 lbs. 11.2 lbs. 16.8 lbs. 22.4 lbs. 28.0 lbs. 56 lbs.
90 1.26 lbs. 6.3 lbs. 12.6 lbs. 18.9 lbs. 25.2 lbs. 31.5 lbs. 63 lbs.
100 1.40 lbs. 7.lbs. 14.0 lbs. 21.0 lbs. 28.0 lbs. 35.0 lbs. 70 lbs.

If you have a large commercial swimming pool, 80,000 - 125,000 gallons, I would recommend to not use more than 1 - 1.5 gallons gallons at a time because if you go too low in one shot, you're going to have another swimming pool problem on your hands.  

This will help reduce your weekly pool maintenance cost. 

Pool Chlorine - Swimming Pool Chlorine & Pool Chlorine Tablets Are Good Water Quality Indicators For Pool Water Maintenance

Chlorine Demand - Chlorine Demand and swimming pool water chemistry.

Chlorine Tablets - Chlorine Tablets & Pool Water Maintenance.

Muriatic Acid - Muriatic acid and swimming pool chemistry.

Pool Water Testing - Pool water testing and the best information on swimming pool test kit.

Pool pH - Understanding swimming pool pH and easy pH chart for perfect pool water balance. 

Total Alkalinity - Total alkalinity and weekly pool water maintenance.

Calcium Hardness - Understand Calcium Hardness & Pool Water Maintenance.

To Recap:

What is total alkalinity?  

Pool alkalinity is the buffer of your pool water maintenance.  Keeping your alkalinity between 80ppm-120ppm will stabilize the chlorine, pool pH, and calcium hardness.

When do I test the pool alkalinity

Test your alkalinity in the late afternoon or early evening when the temperature is a bit cooler.

Where do I test the alkalinity?  

  Test your alkalinity in the deep end of the pool or the furthest away from the filter.

Why do I test the alkalinity?

Testing your pool alkalinity and keeping it at the proper range will help lock in the rest of the chemicals; i.e. chlorine, pool pH, and hardness.

It will lessen pH “bounce”, corrosion of metal parts, scaling in your pool, and skin and eye irritation for your swimmers.

How do I test the pool alkalinity?

Follow the manufacturer’s directions while you’re using your FAS-DPD K-2006 Taylor swimming pool test kit. Test strips are easy but cannot give you a more accurate measurement than the K-2006 kit.

Many times it’s just adding an alkalinity indicator that turns the sample water green. Then simply count the drops until the sample turns red. If you can count, you can do this test with machine-like precision. 

Remember to turn the pump motor OFF when increasing or decreasing your alkalinity or use the aeration technique

Happy Swimming

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What Other Visitors Have Said

Click below to see contributions from other visitors to this page...

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