Pool Chemical Guide for Beginners

The Big 5: Essential Pool Chemistry

1. Free Chlorine (FC): 2-4 ppm

Chlorine sanitizes your pool by killing bacteria and algae. Test and adjust daily during swimming season. Common forms: liquid bleach (cheapest), cal-hypo granules, trichlor tabs (convenient but add CYA).

2. pH: 7.2-7.6

pH affects chlorine effectiveness and swimmer comfort. Low pH = corrosive, irritating. High pH = cloudy water, chlorine less effective. Lower pH with muriatic acid. Raise with soda ash.

3. Total Alkalinity (TA): 80-120 ppm

TA buffers pH, preventing wild swings. Raise with baking soda (sodium bicarbonate). TA naturally drifts down over time.

4. Calcium Hardness (CH): 200-400 ppm

Low calcium = water attacks plaster/grout. High calcium = scale buildup. Raise with calcium chloride. To lower, partial drain and refill.

5. Cyanuric Acid (CYA): 30-50 ppm

CYA protects chlorine from UV degradation. Too much reduces chlorine effectiveness. Trichlor tabs add CYA — this is why they can cause CYA buildup over time.

Testing Schedule

• Daily/every other day: Free chlorine, pH
• Weekly: Total alkalinity
• Monthly: Calcium hardness, CYA

Use our chemical calculator to know exactly how much to add.