Calcium Hardness 4KG $24.77 Calcium Hardness 4KG quantity Add to cart Category: Pool Chemicals Related products Natural Clear ™ Clarifier – 1L $19.77 Add to cart HTH® EXTRA Stabilized Chlorinating Pucks Read more X-tra Strength Algaecide – 1L $24.77 Add to cart C-Clear – 1L $21.77 Add to cart