Sani Marc Summer Smiles 30-07505-05 5kg Protect Cell Ultra 3 in 1 Salt Cell Protector is designed to prolong the life of salt cells, delay corrosion, leave pool water crystal clear and improve bather comfort with just one yearly application each spring. Protect Cell Ultra 3 in 1 also increases the efficiency of salt chlorine generators to improve water quality. Its balanced pH formula will not affect water parameters.