The Nu-Calgon 4173-04 is the Evap-Treat with 6RST Micromet and prevents scale and corrosion in evaporative coolers. For over fifty years, a specialized slowly soluble, food-grade inorganic phosphate known as Micromet has been used to stabilize or “sequester” hardness minerals, and thereby avoid or prevent scale formation in ice machines, cooling towers, humidifiers, etc. For evaporative coolers, a special form of this glassy phosphate known as 6Rsp Micromet has been used effectively in preventing scale and maintaining equipment efficiency. It is NSF-certified, and it is the active ingredient in Evap-Treat. Since evaporative coolers are an established and proven method of cooling and since it is nearly impossible (due to expense, practicality, etc.) to use mineral-free water, a procedure or preventative maintenance program for dealing with the scale-forming minerals must be utilized so that scale is prevented and the equipment operates at optimum efficiency. THE NU-CALGON 4173-04 EVAP-TREAT WITH 6RST MICROMET IS FOR PROFESSIONAL USE AND SHOULD ONLY BE USED IN ACCORDANCE WITH ALL REGULATIONS AND PROPER SERVICE PRACTICES. PLEASE SEE PRODUCT LABEL OR CONTACT NU-CALGON DIRECTLY FOR USE INSTRUCTION. IT IS RECOMMENDED TO UTILIZE THE APPROPRIETE PPE (PERSONAL PROTECTIVE EQUIPMENT) DURING APPLICATION.