The G.A.S Intelligent Humidity Controller is a clever piece of equipment which can automatically monitor and control the humidity levels of a growing environment. Control your humidity and optimize the VDP - the amount of pressure put on plants to move water through them (transpire), therefore optimizing nutrient uptake and growth. Controlling the VDP has a large effect on the growth of a plant, as it dictates how fast or slow they lose water. Can be used to monitor humidity based on air temperature, plant temperature, time of day or even the growing stage of the plant. Safe to be used 24hr/day. Perfect for use with the SonicAir 10L or Sonic Air Pro.