So you have followed our guidelines, and you see the importance of VPD. Now how are you going to turn these plant vitality readings into happy crops?

VPD value too low?
Assuming the temperature is meeting your setpoint, and the lighting is at an optimum height, the best way to raise the VPD value is too lower the humidity. Raising the temperature would be an alternative option if dehumidifying is not possible.

VPD value too high?
Your light fixtures are at the required height and the temperature is where it should? Nothing else to do than raise humidity! don’t be afraid to go towards 75% if you have to. The critical point is around 80% don’t go over or you risk fungi related trouble

My VPD value is too high in the daytime and too low at night. Now what?

Invest in proper, and I mean serious humidifying equipment for the daytime and de-humidifying equipment in the night time.Make sure they don’t both operate at the same time. Switch the humidifier for instance with lights and the de-humidifier with a heater. If you run an air-conditioned operation, de-humidifying should not be a problem…