Pool pH: how to raise or lower it
The ideal pool pH (7.2 to 7.6), what happens when it's too high or too low and how to correct it without getting the dose wrong.
2 min read
pH tells you whether the water is acidic or alkaline. In a pool, the ideal is 7.2 to 7.6: comfortable for the eyes and the range where chlorine works well.
High pH (above 7.6)
- Chlorine loses strength and the water goes cloudy easily.
- White scale builds up around the edges.
- Lower it with pH reducer (pool acid or dry acid).
Low pH (below 7.2)
- Eyes and skin sting, and metal parts of the pump and ladder can corrode.
- Raise it with pH increaser (soda ash).
"The pH won't go up" or "won't stay put"
It's almost always the alkalinity. With low alkalinity, the pH swings every day. Fix the alkalinity first (80 to 120 ppm), then the pH.
How to add it
Dilute the product in a bucket of pool water (always the product into the water, never the other way round).
Pour it around the edge with the filter running.
Add about 3/4 of the dose, wait 4 to 6 hours and test again.
Only add chlorine once the pH is right.
The right dose depends on the size of your pool and the product you have. The calculator works it out in spoons and cups.
Calculate the dose now