Alkalinity calculator
Add about 6.8 lbs of baking soda (sodium bicarbonate) to raise TA by 30 ppm. Add in thirds, circulating and retesting between.
Treat this as a starting dose: add less than the full amount when unsure, circulate for a few hours, retest, repeat. Always follow your product's label.
Raising pH sounds simple, but the common tool — soda ash — also shoves alkalinity up, so it's easy to fix one number and wreck another. The trick is choosing the right raiser for your situation. Here's how to lift pH without sending alkalinity out of range. Follow product labels and confirm your volume.
When pH is too low
Pool pH belongs in the 7.2–7.8 range, ideally 7.4–7.6. Below that, water turns corrosive — it can etch plaster, corrode metal fittings and equipment, and irritate swimmers' eyes and skin — and chlorine can become harshly aggressive. So a low pH reading needs correcting promptly. Test pH and total alkalinity together first, because your choice of raiser depends on where alkalinity sits, not just pH.
The two tools do different things
There are two common pH raisers, and picking right is the whole trick. Soda ash (sodium carbonate) raises pH strongly and also raises total alkalinity noticeably — great when both are low, but it'll overshoot alkalinity if TA is already fine. Sodium bicarbonate (baking soda) raises alkalinity a lot and pH only a little. And aeration — agitating the water with jets, fountains, or a bubbler — raises pH without adding to alkalinity at all. Match the tool to which numbers you actually need to move.
Choosing the right approach
Let your two readings decide. If both pH and alkalinity are low, soda ash fixes both at once — the efficient choice. If pH is low but alkalinity is already in range, reach for aeration instead, or use soda ash sparingly, so you don't drive TA too high. If alkalinity is low but pH is only slightly low, sodium bicarbonate handles both gently. This is how you raise pH "without wrecking alkalinity" — by not defaulting to soda ash when TA doesn't need the boost.
Add slowly and retest
Whatever you choose, dose in stages with the pump running. Add a measured amount per the label for your volume, let it circulate for a few hours, and retest before adding more — overshooting pH means you then have to bring it back down with acid, chasing the number. Soda ash in particular can cloud the water briefly if dumped in fast, so add it gradually and let the filter clear any haze. Aeration is slow but essentially foolproof; just run the water agitated and let pH climb.
Confirm both numbers
Finish by checking the pair. Once pH sits in the 7.2–7.6 range and alkalinity is still in its 80–120 ppm band, you've done it right — both in range, neither wrecked. Retest after everything circulates and again in a day to confirm it holds. If pH keeps crashing low, look for causes like acidic rain, heavy fill water, or overuse of acid, and fix that rather than re-dosing constantly. Our pH and alkalinity calculators help size the doses so you land both in range together.
Frequently asked questions
How do I raise pH in a pool?
Test pH and total alkalinity, confirm pool volume, then add a labeled pH increaser such as soda ash in small doses. Circulate the water and retest before adding more.
What raises pH without raising alkalinity too much?
Aeration can raise pH without adding chemicals, but it is slower. Borax is sometimes used to raise pH with less alkalinity impact than soda ash, but you should follow product labels and understand the other chemistry it affects.
Will baking soda raise pool pH?
Baking soda mainly raises total alkalinity. It can nudge pH upward, but it is usually not the best tool when pH is low and alkalinity is already acceptable.
Can I swim right after raising pH?
Follow the product label. In general, circulate the water, retest pH and sanitizer, and do not swim until the water is clear and readings are in the safe range.
Why does my pool pH keep dropping?
Low alkalinity, acidic chemical use, rain, fill water, heavy organic load, and some sanitizer routines can pull pH down. Track the trend instead of correcting one test result over and over.
