Free tool
pH Calculator
Soda ash to raise pH, muriatic acid or dry acid to lower it — dosed to your exact pool volume.
How to use this calculator
- 1Enter your pool volume
Don't know it? Use the Pool Volume Calculator first — this tool is built to work with that gallon figure.
- 2Choose raise or lower pH
Enter your current and target pH readings from a test kit or strip.
- 3Pick your product
Raising uses soda ash. Lowering supports muriatic acid (enter your product's exact concentration) or dry acid.
- 4Read your dose
The calculator shows exactly how much product to add, in ounces or pounds.
Frequently asked
Questions about pH adjustment
Does total alkalinity affect this calculation?
Yes, significantly. Total alkalinity acts as a buffer — the higher your TA, the more product it takes to move your pH the same amount. This calculator gives a starting-point estimate; if your TA is well outside 80-120 ppm, expect the real result to differ.
Should I add all the chemical at once?
No. Add chemicals gradually, let your pump circulate for a few hours, then retest before adding more. Adding a large dose all at once — especially muriatic acid — can overshoot your target and stress pool surfaces or anyone swimming nearby.
What's the difference between muriatic acid and dry acid?
Both lower pH, but muriatic acid is a liquid (dosed by volume) and dry acid (sodium bisulfate) is a granular powder (dosed by weight). Dry acid is easier to handle and store but usually costs more per treatment. This calculator supports both.
Can soda ash raise total alkalinity too?
A little — soda ash (sodium carbonate) raises both pH and, to a lesser extent, total alkalinity. If your alkalinity is already high, consider aeration or a smaller, more gradual soda ash dose instead.