Understanding Pool pH, Pool Alkalinity, & pH Definition In Chlorine & Saltwater Pools.
The pool water pH is important. It's a measure of its total acid and alkalinity balance. This means the relative proportion of acids in the water. Simply, the pH of water that is either too acidic or too alkaline.
I prefer using liquid pool acid rather than sodium bisulphate so as not to increase sulfates so much. The amount of sulphates it takes to skew the water chemical results is debatable, at best.
Lowering pH using muriatic acid (pH minus), Sodium Carbonate/Soda Ash and one of the good pool water test kits, not pH indicator strips, can help with your swimming pool chemical maintenance.
This is true for salt water swimming pools as well, and will help reduce any cloudy pool water.
Understanding your pool water pH is the first step in getting it right the first time.
The definition of pH is the negative log of hydrogen ion concentration in a water-based solution. It's an abbreviation for "power of hydrogen". It has a range of 0 - 14 and 7.0 is neutral. Anything 6.9 and under is acidic and 7.1 and over is alkaline.
It has a range of 0 - 14 and 7.0 is neutral. Anything 6.9 and under is acidic and 7.1 and over is alkaline. Your pool pH should be between 7.2 - 7.8.
When your swimming pool pH level is 5.5, the pool chlorine is 100% effective. At around 7.2-7.4 the chlorine is about 50% effective. At a higher pool water pH of 8.0-8.2 and above, the chlorine effectiveness drops to 25%.
By keeping your level between 7.8-8.2 or higher, you’re actually wasting almost 75% of your chlorine! On the flip side, at 7.0, you'll use too much pool acid, but the chlorine is a bit more effective. The pH in water will naturally rise through the result of bather load, splashing around, and the use of waterfalls and slides. This is called "out-gassing" or aeration. When a swimming pool is unbalanced, out of control, and doesn't have the proper pool water chemistry, it can be the most frustrating time for a pool owner.
If your fill water is already a bit high (7.8-8.2), count your blessings. Just a little pool acid or pH minus (maybe ½ gallon or even less) will bring your level down. Take care in adding any pH minus or pool acid at pool start up (opening pool). This will decrease any chances of swimming pool stains.
If your fill water is reading 7.2, great!! Allow your swimming pool pH level it to come up naturally and make small adjustments only when needed. Use a little Sodium Carbonate, soda ash, 20 Mule Team Borax, or Arm & Hammer Washing Soda.
When calculating pH, don’t “manhandle” your swimming pool chemistry in a single-shot. A gallon of pool acid. Then 5 lbs. of soda ash as a pH increaser to bring the pH back up.
Bad for the water, the pool plaster, and might increase your chances of cloudy swimming pool water, green pool water, blue-green algae, and poor swimming pool water chemistry.
This is also true for a salt water pool system that use salt water generators which produce hypochlorous acid. Your pool is smart and will tell you exactly what it needs if you’re in tune with it. By following this advice on swimming pool water chemistry and care, you're on your way to being the envy of the neighborhood. There are also ways to conserve water and pool chemicals. One of the best and cheapest is a solar swimming pool cover. It decreases evaporation and pool chemical use.
Remember: Just tiny corrections are needed once the proper balance has been established.
Go To:Swimming Pool Care > Pool Chemistry > Pool pH
Click below to see contributions from other visitors to this page...
pH Too Low & Problem With Alkalinity
The pH is so low it does not register - I buy pH plus and add all summer but it never comes up. I usually add 5 lbs and wait a day and add another 5 lbs. …
Soda Ash Overdose Not rated yet
I overdid my 14 foot above-ground pool on soda ash to raise the pH and overall alkalinity, and now I can’t see anything beyond the top. I treated it …
How Much Baking Soda To Raise pH Level Not rated yet
We just opened our 22,000 gallon above ground pool. We also just purchased a new DE filter and pump. My husband used 5 bags of shock, we put algeacide …
Staining And Trying To Raise pH Not rated yet
I have a 40,000 gallon vinyl lined inground pool. I am having a few issues that I am trying to resolve. Cl levels are 2-4 ppm. I just addded 26 lbs …
pH Too High In Saltwater Not rated yet
My pool is 22x52. My pH is 8.4 and free chlorine is 0/0. Alkalinity is 80-120. Cyanuric acid is 30-50 and 0 on copper. Water is milky. What can …
Can't Get pH To Go Down Not rated yet
I have a 3,700 gal easy set pool...set it up and shocked water turned yellow green instantly - was told I had excessive amounts of iron in water. …