Using EZ Kleen preventative maintenance fluid on a regular basis ensures a longer life for the heat exchanger in Ultratec fog machines by reducing blockage. Instructions: 1. Run EZ Kleen through machine after 8-12 hours of operation for 5-6 minutes. 2. Then use any Ultratec Fog Fluid for 2 minutes. *Do not use this fluid in the Radiance Hazer.