$50.99 Clorox Pool&Spa Shock Plus 6x1 lb in the Pool Shock department at Lowes.com
Rx Clear Multi-Functional 4-in-1 Swimming Pool Shock | 99% Sodium Dichloro-s-Triazinetrione 
Amazon.com : 2-Pack Chlorine Dichlor Granules sanitizer shock for Spa, Hot Tub, Pool - 2 x 2 lb 
