Estimate muriatic acid to lower pH, or soda ash to raise pH — based on gallons + TA.
This tool provides estimates for educational use. Real results vary with circulation, test accuracy, product strength, aeration, temperature, and measurement error.
Pool pH measures how acidic or basic the water is. This calculator estimates how much muriatic acid is needed to lower pH or how much soda ash is needed to raise it. Because total alkalinity affects how strongly water resists pH changes, this calculator also considers your TA for a more realistic estimate.
Add chemicals in smaller portions, allow the pool to circulate, then retest before making another adjustment. Trying to change pH too quickly often leads to overshooting the target.
Proper pH helps chlorine work efficiently while keeping swimmers comfortable and protecting pool equipment. Low pH can make water aggressive, leading to corrosion and eye irritation. High pH reduces chlorine efficiency and increases the chance of cloudy water and calcium scale.
Most residential pools operate best between 7.2 and 7.8, with many owners targeting around 7.4–7.6. The ideal value also depends on total alkalinity, calcium hardness, temperature and CSI.
Most pools benefit from testing at least two or three times each week, and more often during hot weather or heavy swimmer use.
Rain can influence pH by diluting pool water and introducing contaminants, so it is a good idea to retest after major storms.
Because the two work together, test both and make adjustments with the overall water balance in mind.
If your pH keeps drifting up every week, don't just keep pouring in acid. Check your total alkalinity, aeration, and CSI. Solving the cause is easier than constantly correcting the symptom.