How to Increase Total Alkalinity in a Swimming Pool

How to Increase Total Alkalinity in a Swimming Pool



Testing your pool's alkalinity is a critical part of ensuring your pool's water is optimally balanced. Alkalinity, also referred to as "total alkalinity," refers to  the measure of the ability of the water to maintain a desirable pH when acid is added to the water.  The optimal number for water in a swimming pool or hot tub, is between 80 and 120 parts per million (ppm) for gunite and concrete pools and fiberglass pools, and 125-170 ppm for painted, vinyl and fiberglass pools. When pool water is in this range of alkalinity, it will balance or stabilize the pH level at a neutral number. High pH means the water is too alkaline. Low pH means the water is too acidic. Either way, water that is out-of-balance is corrosive. If you maintain your pool regularly however, your TA (total alkalinity) will not usually vary much.

Water that is too alkaline or too acidic will damage your pool liner, any metal or plastic fixtures and any surfaces that the water touches. Keeping your water's pH (alkaline/acid) levels balanced will ensure your pool isn't damaged and your swimming experience is a pleasant one. Water that is too alkaline will cause your chlorine to lose its effectiveness as a disinfectant. It will also turn your water cloudy and irritate swimmers eyes and dry their skin. Water with low alkalinity will etch pool walls, corrode metal, turn water green and cause swimmers eyes to burn.


Step 1-Test Your Pool Water

Using a pool water testing kit, dip the water collector under the water to a depth of at least 18 inches. Add your reagents and test the color against the chart provided with your kit. If the level is within 80-125 ppm for gunite or concrete pools, or 125-170 ppm for painted, vinyl and fiberglass pools, you don't need to take any further action.


Step 2-Calculate Water Alkalinity

If your water test shows your TA (total alkalinity) is too low, you'll need to raise it by adding sodium bicarbonate. 

There a handy web based calculator that makes it very easy to figure out the proper amounts of chemicals to add called The Pool Calculator.

Click this link for THE POOL CALCULATOR


Step 3-Add Sodium Bicarbonate

Once you have determined how much sodium bicarbonate to add, make sure the amount is within the safe levels for your pool size. You should only add 2.20 pounds of sodium bicarbonate for every 11,000 gallons of water every four days.  Measure the amount you need to add to a dry bucket. Wearing eye protection and gloves, add the sodium bicarbonate broadcast it (spread) by shaking or sprinkling it into the deep end of the pool. Don't just dump it into the pool. It will clump and sink and take longer to disperse. 

Step 4-Retest And Reapply

Retest after 3 or 4 days. Raising the alkalinity means adding sodium bicarbonate. Sodium bicarbonate should  only be added at a rate of 2.2 pounds for every 11,000 gallons of water every four days. Test your pH levels as well your TA levels because sodium bicarbonate and any other chemical will affect the pH balance as well.


Remember to test ALL of your chemicals and use The Pool Calculator to determine your saturation index and ensure your pool is properly balanced !