Total alkalinity: what it is and how to fix it

What total alkalinity does in a pool, the ideal range (80 to 120 ppm) and how to raise or lower it.

2 min read

Total alkalinity works like a shock absorber: it stops the pH changing with every rain or every product. The ideal range is 80 to 120 ppm.

Low alkalinity

• The pH is unstable and drops easily.
• Raise it with buffer (sodium bicarbonate).
• Add it, wait 6 hours with the filter running and test the pH again before touching it.

High alkalinity

• The pH gets "stuck" high and the water tends to go cloudy.
• Lower it with pH reducer, in 2 or 3 doses on different days.
• Keep the water well agitated (waterfall, jets) so the pH comes back up without the alkalinity rising with it.

Always the same order: alkalinity, then pH, then chlorine.