pH and Alkalinity are usually linked, and it is important to maintain your pool’s pH levels. Too high or too low can be harmful to your pool and swimmers, but how do you raise or lower the pH and Alkalinity of your pool?
The ideal pH of pool water is 7.2 to 7.8, while the ideal alkalinity of pool water is 80 to 120ppm. To raise the pH & Alkalinity of your pool, add soda ash. To lower the pH & Alkalinity of your pool, add muriatic acid. Use bicarbonate of soda to raise Alkalinity without raising pH and use dry granular acid to lower your Alkalinity without lowering pH.
You will also need to know how much acid or soda ash to use depending on your pool size and the pH and Alkalinity of your pool, which I will cover in the rest of this post.
You also need to know how out-of-balance pH and Alkalinity can affect your pool and your swimmers.
It is also important to understand what exactly pH and Alkalinity mean, let’s explore that first.
What is pH and Alkalinity in pool water?
“In simple terms, pH is the concentration of acid protons [H+]. On the other hand, the alkalinity of a solution is its ability to neutralize acids. Alkalinity consists of ions that incorporate acid protons into their molecules so that they are not available as a free acid that can lower the pH.”American Water Chemicals, Inc.
pH and Alkalinity are usually linked. If your pH is high, your Alkalinity is more than likely going to be high and if your pH is low, then your alkalinity is probably going to be low as well.
If your alkalinity is low, then that means your pool is too acidic.
Balancing alkalinity is simple. If alkalinity is high, you need to add muriatic acid and if it is low, you need to add baking soda.
IMPORTANT: It is possible to have low pH with high Alkalinity, which we will discuss at the end of the article.
Testing Your Pools pH and Alkalinity
Your pool waters pH should be between 7.2 and 7.8 while your Alkalinity should be 80-120 ppm (parts per million). You should already be testing your pool’s pH levels regularly so that you will know when it has dropped too low.
I recommend the Aquachek 7 test strips. This is a 7 in 1 test strip designed for pool water and will test your pH as well as your total alkaline along with other important factors.
Is High pH and Alkalinity Bad?
Yes, high pH and Alkalinity to bad for your pool. When your pH gets too high your chlorine will not be able to disinfect your water properly.
How to lower pH and Alkalinity in Pool Water.
To lower the pH of your pool water, you will need to add muriatic acid. You want to add about 1lb of muriatic acid for every 10,000 gallons of pool water.
I highly recommend you add only 1lb of acid at a time, allowing a few hours to pass. Leave the pump running to help mix and disperse the chemicals into the water. Test the water again using a test strip and repeat this process if needed. Repeat this process until you have reached the desired pH and alkalinity levels.
Is Low pH and Alkalinity Bad?
Yes, low pH and Alkalinity are bad for your pool as well as the swimmers. Low pH / acidic water can be problematic to swimmers as well as the surface of the pool and pool equipment.
Swimming in pool water with low pH can cause corrosion of the pools’ surface and can cause irritation in the eyes and skin of swimmers.
What causes Low pH and Alkalinity?
Things that can cause your pool to become acidic (low alkalinity) is
- Acid rain.
- Acidic body oils.
- Uric acid from people peeing in your pool.
- Too much chlorine.
How to Raise pH and Alkalinity in Low pH Pool Water.
Go to a pool supply store and get some soda ash.
Soda ash is a cheaper alternative to baking soda but it does cloud up your water a bit. This is easily cleaned out by your pool’s filter. Baking Soda is clearer, but it will only raise your Alkalinity and not your pH.
IMPORTANT: If you want to raise your Alkalinity ONLY, separate to the pH, then use baking soda. More on this at the end of this article.
When you go to a pool supply store, they will probably try to sell you products you don’t need. All you need to raise your pH and Alkalinity levels is soda ash.
1.5lbs of soda ash per 10,000 gallons of water raises the alkalinity of that water by about 10ppm.
Measure about a 1lb of soda ash or baking soda and sprinkle it all around your pool. Leave your pump running to help to disperse the chemicals in your pool. Allow around 6 hours, then test the pH and Alkalinity of your pool. Repeat this process until you have reached the ideal pH and Alkalinity levels.
How do I lower the Alkalinity of Water Without Raising the pH?
If your Alkalinity is too low, but your pH is good, then you need to raise the alkalinity of the pool without raising the pH. To do this, use dry granular acid.
Start off by adding 1lb for every 10,000 gallons of water. Let your pool pump run and mix the chemicals in for a few hours and test again. Repeat this process until you have reached the desired Alkalinity.
How do I raise the Alkalinity of Water Without Raising the pH?
Conversely, if your pool water is high in Alkaline, but the pH is balanced, then you will need to lower the alkalinity of the pool without affecting the pH level. To do this, you can use baking soda, also known as bicarbonate of soda.
You can use a similar process as above, add 1lb of baking soda per 10,000 gallons of pool water. Leave the pump running and wait a few hours. From there you can add more and repeat the process until you have reached the desired Alkalinity.
Conclusion
You want to keep your pH and Alkalinity in balance for the health of your pool and swimmers. So be sure to check these levels regularly.
Chemicals, sweat and even peeing in your pool can throw your pH and Alkalinity out of balance, but this is relatively easy to correct.
To raise the pH and Alkalinity of the pool together, we add soda ash. This is easy to buy from any pool supply store, but have your guard up because they will try to upsell you with fancy products. Don’t fall for it, soda ash works just fine.
Soda ash will temporarily make your water cloudy, but this gets filtered out in time with no problems.
To lower the pH and Alkalinity of your pool together, add muriatic acid.
If you have high or low Alkalinity, but your pH is balanced, then you need to raise or lower your Alkalinity without affecting your pH.
To raise your pool’s Alkalinity without affecting your pH, add baking soda (bicarbonate of soda).
To lower your pool’s Alkalinity without affecting your pH, add dry granular acid.