Ideal pH Range for Pools: 7.2 – 7.8
Testing Pool pH: Test your pools pH level regularly (ideally twice per week) with a test kit or test strips. In addition, we recommend periodically (once per month) taking a water sample to a dealer test station to verify the results.
One of the biggest parts of pool care is maintaining the chemical balance in your pool. Pool chemistry is not only necessary to keep your pool clean and safe, maintaining a proper pH level in your pool is essential in order for other chemicals to do their work. Chlorine is much less effective at higher pH levels; in fact, at a pH of 8.2, chlorine is only 15% effective. The optimal pH range for your pool is 7.2-7.8. Is your swimming pool well balanced? Find out with our Langelier Saturation Index (LSI) calculator.
If using a FROG® System, use only FROG Test Strips to help you dial in the low chlorine or bromine level used with FROG minerals. With standard test strips you could over chlorinate which wastes money. Using FROG Test Strips can help your chlorine pacs and bromine cartridges last up to 50% longer!
A low pH level means your pool water is acidic, which can not only cause corrosion of pool surfaces and equipment, it can also reduce your ability to control total alkalinity and cause an uncomfortable swimming experience for your family and guests, as acidic water will sting eyes and remove the natural oils on skin, leaving it dry and itchy.
Why is my pools pH low?
Many things can lower the pH in your swimming pool:
- You might have added too much pH reducer in an attempt to lower the pH of your swimming pool
- Your local water source may have a low pH, this may be the culprit if you are continually having to add pH increasing chemicals
- Heavy pool usage can introduce a large amount of natural contaminants (i.e. saliva, body oils, sweat, etc). All of these natural contaminants can lower the pH level in your pool.
- Organic matter such as grass, insects and dust are common organic matter that can lower the pH
- Rain picks up impurities in the air as it falls, raising the acidity, thus lowering your pools pH
- Shocking your pool will lower the pH regardless of what type of shock you use
How to raise your pools pH
There are two main ways to raise/increase the pH in your swimming pool. The first is to use chemicals, typically called a pH increaser, pH plus or pH raise, the most common of which is soda ash. The general rule of thumb when adding soda ash to your pool is, 1 pound of soda ash for every 10,000 gallons of pool water to raise the pH by 0.1. If you don’t know how many gallons of water are in your pool, you can calculate it here with our Pool Volume Calculator. Once you’ve added the soda ash, you’ll want to wait at least 6 hours before retesting your pools pH level.
The second way is to raise your pools pH by adding new water. Water from your hose is typically slightly higher in alkalinity than your swimming pool water should be, thus adding new water should bring up your pools pH level a bit.
When your pool has a high pH level, it means the water is basic and over time high pH levels can cause the water to scale on your pool filters, plugs, pipes and other equipment. Water scale can reduce the water circulation, thus increasing water pressure within the circulation system and putting strain on your pool equipment.
Why is my pools pH high?
Below are a few reasons why your pools pH level may be a bit high:
- Local water source may have a higher than normal pH level
- You might have added a little too much pH increaser when you saw your pools pH level was low
How to lower your pools pH
First test your pools pH level, to help you determine the best type of chemical to use to lower your pools pH. If you’re using a FROG® System use FROG® Test Strips which are designed to dial in the low chlorine or bromine levels used with FROG® Minerals.
There are two main chemicals typically used to decrease pH in pools, muriatic acid and dry acid (also known as sodium bisulfate). Although they are designed to do the same thing, pay attention to which chemical you are using, because how you add the chemical differs.
Struggling with pH? Did you know FROG Fresh Mineral Water Systems help maintain pH balance for cleaner, clearer and softer water with 50% less chlorine?
Frog’s Nutty Professor Sergei on pH