CuZn The Spa Core Mineral Purifier for Spa, Hot Tub & Jacuzzi All Natural, Non-toxic, Chemical Free Mineral Purifier for Hot Tub Water Treatment! (have a skimming basket in your spa? search asin#B00091ROUE) (have a pool too? search asin#B000HHPQ3C) Balances pH, Controls Bacteria & Algae Growth, Removes Existing & Prevents Future Hard Calcium Scale Build Up. One CuZn SpaCore will Purify Water for 3-5 Months Universal, One Size Fits All. The SpaCore CuZn is Flexible and Can be Cut to Size for Unique Filter Designs. The Following Products are Typically All That is Needed When Using the Spa CuZn System: Scum Bug, Clarifier & Potassium Monopersulfate Based Shock 60 Day Money Back Guarantee! If You aren't Completely Satisfied with the Spa Core CuZn, We'll Give You a Full Refund Eliminates the Need for Chemistry, Testing & Nearly All Expensive Chemical Additives. Simply Add a Non-chlorine "Mini Shock" on a Weekly Basis (see product description below for details)