I have for sale a Tetra CO2 system. Used only 3 months. If you are interested in purchasing it please email me personally. $50.00+shipping (firm). Keith L. Webb Lead Civil/Structural Engineer S&B Engineers and Constructors, Ltd. 3535 Sage Road Houston, TX 77056 Phone: (713) 845-5466 Fax: (713) 622-2069 Internet: klwebb at sbec_com