Grozone Control designs and manufactures quality climate controllers for your indoor garden and greenhouse. From precise Co2, RH and Temperature controllers, to cycle timers, tempstats or CO2 Generators, we have all you need to help you control the climate inside your indoor garden or greenhouse. Expect high quality products with the best warranty in the industry. Lowest return rate of the business. Period. Be R3 Compliant : Reliable Products, Reliable Service, Reliable People.