Calcium Hardness – 2KG $14.77 Calcium Hardness - 2KG quantity Add to cart SKU: 72216 Category: Pool Chemicals Related products HTH Extra Algimycin Algaecide – 1L $29.77 Add to cart HTH® EXTRA Stabilized Chlorinating Pucks Read more pH Plus – 2KG $19.77 Add to cart Sequa-Sol ® Stain Control – 1L $21.77 Add to cart