Reference 2 min read Updated 2026-06-01

Shock Dosage Matrix

v2026.07

Quick reference for how many pounds of calcium hypochlorite (65%) are needed to shock a pool by volume and purpose.

These doses are for 65% calcium hypochlorite (cal-hypo). Adjust proportionally for other concentrations. Always add pre-dissolved to the pool, never to the skimmer.

Cal-Hypo (65%) Shock Dose by Pool Volume

Pool VolumeMaintenance / Breakpoint CC 1 ppm (10 ppm raise)Breakpoint CC 2 ppm (20 ppm raise)Green Pool (30 ppm raise)
5,000 gal0.64 lb1.28 lb1.92 lb
8,000 gal1.03 lb2.05 lb3.08 lb
10,000 gal1.28 lb2.57 lb3.85 lb
12,000 gal1.54 lb3.08 lb4.62 lb
15,000 gal1.92 lb3.85 lb5.77 lb
18,000 gal2.31 lb4.62 lb6.93 lb
20,000 gal2.57 lb5.13 lb7.70 lb
25,000 gal3.21 lb6.42 lb9.62 lb
30,000 gal3.85 lb7.70 lb11.54 lb

Notes

  • Doses use the site-wide approved mass-balance formula (ppm increase x gallons x 0.013344 / 65) for 65% calcium hypochlorite. A breakpoint dose is 10x the combined-chlorine (CC) reading, so a CC of 1 ppm requires the same 10 ppm FC raise as a routine maintenance dose -- the two leftmost dose columns are the same figure for that reason, not an error. Green pool dose targets a 30 ppm FC raise. These figures are a manual reference; the live shock calculator offers fixed presets (5, 10, 15, or 20 ppm) rather than the full range shown here.
  • Pre-dissolve granular shock in a bucket of water before adding to pool.
  • Add after dark. Run pump overnight. Do not allow swimming until FC drops below 5 ppm.
  • For 73% cal-hypo, multiply doses by 0.89.
Sources:
  1. Taylor Technologies — Pool/Spa Water Chemistry Reference

Last reviewed: 2026-06-01