Does Rain Increase Pool pH

Since rain is diluting your pool, you may expect that it will reduce the acidity of your pool water. However, all rain in the US is acidic due to pollution, so rain actually decreases your pool’s pH – in other words, the pool water becomes more acidic.

How does rain affect pH?

Rain is initially neutral in pH, a perfect 7.0 – but very quickly absorbs low pH contaminants as it falls through the sky. … Such rain is not usually extremely acidic, but may fall in the 5.5-6.5 pH range, low enough to affect your pool pH levels, again causing a need to raise your pH.

Should I shock pool after rain?

Shock the pool It’s not time to fix your pool chemistry just yet – that said, there’s nothing wrong with giving your water a little boost. After heavy rainfall, your pool’s chlorine levels will be much lower from fighting off contaminants. Shocking your pool replenishes the chlorine lost from the rain.