Pool & spa
Pool pH Calculator
Acid or soda ash to move pool pH to where it should be.
Result
Dose against a test result, never against a schedule. Add chemicals in stages with the pump running, wait for a full turnover, then retest before adding more. Never mix chemicals, and never add water to acid. Where a product label differs from the figure here, the label wins. pH dosing is strongly affected by total alkalinity, which acts as a buffer. Low alkalinity makes pH swing wildly and acid overshoot; high alkalinity makes pH stubborn and drift upward. Fix alkalinity before chasing pH. Acid is dangerous: add acid to water, never water to acid, and never mix it with chlorine.
Get a Free Business AuditQuestions
About this calculator
Why does pH keep rising?
Aeration. Fountains, waterfalls, spa jets and salt cells all drive carbon dioxide out of the water, which raises pH. High total alkalinity makes it worse.
What pH should a pool hold?
Between 7.2 and 7.8, with 7.4 to 7.6 the usual target. Below 7.2 the water corrodes metal and etches plaster; above 7.8 chlorine loses effectiveness and scale forms.
Should I fix pH or alkalinity first?
Alkalinity. It is the buffer that holds pH steady, and adjusting pH while alkalinity is out of range means doing it again next week.
The formula
roughly 8 fl oz of 31% muriatic acid per 10,000 gallons lowers pH by about 0.1
Put this calculator on your site
Free to embed. Paste this where you want it to appear. It stays up to date automatically because it loads from BDEVY.
Please keep the attribution line. It is the only thing we ask in return.
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.