Chemical dosage for any pool.
Pick what to adjust, enter current and target readings, and get exact dosing in oz, fl oz, or pounds. Covers free chlorine, pH, alkalinity, calcium hardness, CYA, and salt.
Pool + reading
Industry standard math from NSPF / pool service references. Real world dosing varies with source water and TA. Re test 30 minutes after dosing and adjust.
Recommended dose
For a 20,000 gallon pool to reach 3 ppm free chlorine from 1 ppm, add:
Calcium hypochlorite (cal hypo, 65%)
Raises calcium hardness slightly. Best for dry storage.
4.9 oz
Recommended
Liquid chlorine (12.5% sodium hypo)
Raises pH slightly short term. No CYA.
4.3 fl oz
Trichlor (90%)
Adds ~0.6 ppm CYA per ppm FC. Lowers pH.
3.5 oz
Dichlor (56% / 62%)
Adds ~0.9 ppm CYA per ppm FC. pH neutral.
5.7 oz
Want this on every visit?
Pooly auto calculates from each reading + pool size.
About this calculator
How dosing is calculated
Each chemical changes a target reading by a known amount per ounce, fluid ounce, or pound per 10,000 gallons. Calculations scale linearly with pool volume. Source values come from NSPF and standard pool service references (PoolMath, Service Industry News, Aqua Magazine).
Results are starting points. Source water hardness, current TA, and bather load affect outcomes. Re test 30 minutes after dosing and adjust as needed. Never combine chemicals before adding to the pool.
Related reading