calcs.homes
calcs.homes
Muriatic acid (31.45%) lowers both pH and total alkalinity — pick which one you're adjusting and enter your reading to get an exact dose.
Estimate only — always add acid to water, never water to acid. Wear eye protection.
We take the difference between your current and target reading, divide pool volume by 10,000 gallons, and multiply by a dosing constant: 80 fl oz per 10,000 gallons per full pH point when lowering pH, or 26 fl oz per 10,000 gallons per 10 ppm when lowering total alkalinity. The 31.45% figure is standard retail-strength muriatic acid, and the dose only ever comes out positive — it can't raise either reading.
31.45% hydrochloric acid drops pH and total alkalinity at the same time, since both readings track the same carbonate and hydrogen-ion chemistry the acid attacks directly. Pool professionals add it in small increments, run the pump to circulate fully, and retest both numbers rather than just one — chasing pH alone can leave alkalinity too low, and vice versa, throwing off overall water balance.
It's a strong acid — wear gloves and eye protection, work in a ventilated area, and always add acid to water (never the reverse) to avoid a violent reaction.
It affects both at once, but proportionally more of its effect shows up in alkalinity. Pool pros often dose for alkalinity, let it circulate, then fine-tune pH separately.