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 (10 ppm)Breakpoint CC 1 ppmBreakpoint CC 2 ppmGreen Pool (30 ppm)
5,000 gal0.8 lb1.25 lb2.5 lb2.4 lb
8,000 gal1.2 lb2.0 lb4.0 lb3.7 lb
10,000 gal1.5 lb2.5 lb5.0 lb4.6 lb
12,000 gal1.8 lb3.0 lb6.0 lb5.5 lb
15,000 gal2.3 lb3.75 lb7.5 lb6.9 lb
18,000 gal2.8 lb4.5 lb9.0 lb8.3 lb
20,000 gal3.1 lb5.0 lb10.0 lb9.2 lb
25,000 gal3.8 lb6.25 lb12.5 lb11.5 lb
30,000 gal4.6 lb7.5 lb15.0 lb13.8 lb

Notes

  • Maintenance dose raises FC to approximately 10 ppm. Breakpoint dose is 10x the combined chlorine level. Green pool dose targets 30 ppm FC.
  • 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. For liquid chlorine (10%), multiply doses by 6.
Sources:
  1. Taylor Technologies — Pool/Spa Water Chemistry Reference

Last reviewed: 2026-06-01