GLB Calcium Hardness Up 25 lb – Pool Hardness Increaser OEM Filter Set reduced filtration efficiency

reduced filtration efficiency

original hand nuts can crack

original check valve flappers can warp

Salt should be added directly to the pool water and allowed to dissolve fully before operating the salt chlorine generator

Discharging water during cartridge filter cleaning

GLB Calcium Hardness Up 25 lb – Pool Hardness Increaser OEM Filter Set reduced filtration efficiencyLOCAL DELIVERY OR IN STORE PICKUP ONLY GLB Calcium Hardness Up (25 lb) is a professional grade calcium increaser designed to raise calcium hardness levels in swimming pools. Proper calcium hardness is essential for protecting pool surfaces and equipment while maintaining balanced water chemistry. This fast dissolving formula allows for controlled calcium adjustment without clouding water when used as directed. Low calcium hardness can cause aggressive