Bring pH down from 7.69 to 7.50
Muriatic acid (31.45% / 20° Baumé)
3.1 cups (25 fl oz)
- Run the pump so the water is circulating before you add anything.
- Pre-dilute the acid in a bucket of water, then pour it slowly around the deep end with the pump running.
- Brush the area to disperse it and let the pump run for at least 4 hours.
- Retest before adding any more — this dose is deliberately about two thirds of the full correction.
Always add acid to water, never water to acid.
Never mix acid with chlorine, even in an empty bucket.
This assumes a total alkalinity near 100 ppm. If your TA is well off that, the acid demand changes — test it before dosing.
Dry acid (sodium bisulfate): about 1.9 lb (31 oz) instead.
Retest after about 6 hours of circulation.