pH and total alkalinity
Keep pH 7.2–7.8 and TA 80–120. How muriatic acid, dry acid, soda ash and baking soda move them.
Taylor's ideal ranges are pH 7.2–7.8 and total alkalinity (TA) 80–120 ppm[1]. CDC accepts pH 7.0–7.8[8].
Alkalinity
- Raise TA 10 ppm in 10,000 gal: 1.4 lb sodium bicarbonate (baking soda)[1]
- Lower TA 10 ppm in 10,000 gal: 25.6 fl oz of 31.45% muriatic acid, or 2.15 lb dry acid[1]. Lowering TA takes repeated acid doses plus aeration over days.
pH
How much acid it takes to drop pH depends on TA (and CYA, which also buffers). Our calculator works it out from carbonate chemistry[10]: for example, 7.8 → 7.4 at TA 100 in 10,000 gal is about 13 fl oz of muriatic acid. Real pools often need a little more (borates and other buffers), so add in parts and re-test after 30 minutes. Soda ash raises pH (and TA a little).
Always add acid to water, never water to acid. Pour slowly in front of a return with the pump running. Wear eye protection.