A 50-pound tub of calcium hypochlorite shock is what you reach for when the pool needs a real reset, not just a routine dose. HTH Cal-Shock Plus is a granular pool shock designed to knock out the buildup that regular chlorine additions cant touch algae blooms, cloudy water, and the chloramines that cause that harsh chemical smell everyone blames on too much chlorine when its actually too little.This is a bulk container, sized for pool owners who shock regularly through the season or manage a larger pool that eats through chemicals fast. Granular form dissolves for straightforward broadcast application. Made in the USA.Product Type: Cal-Shock, Sub Brand: PlusProduct Form: GranuleContainer Size: 50 lbUsage: PoolProduct Group: ShockCountry of Origin: USA