Total alkalinity

Total alkalinity, often shortened to TA, measures how well water resists a change in pH when acid is added. Dissolved alkaline substances, including bicarbonates, provide this buffering effect. Results are usually shown in parts per million, or ppm. A low TA reading can allow pH to change more easily, but TA does not tell you the water’s current pH or calcium hardness.

Read alkalinity and pH as separate results on your test kit. Adjusting one can affect the other, so follow the order and retesting instructions in your spa’s care guide and on the treatment label. Avoid treating “alkalinity” as another name for high pH. When discussing a result with Legacy Spas’ water-care team, bring both readings and the names of any products recently added.