[goodbye95]

I have been learning lately about vpd and i am experimenting with it with my current grow . I have an ir thermometer and a controller inside my tent which keeps temp and Rh strictly at the values i put. My question is this.
If the leaf temperature is higher than the tent temperature does it mean that my rh is too high and no transpiration occurs to cool the plant? Or the rh is too low which gets the lvpd higher and stresses the plant to the point that it does not transpire again?

 

[Moe.Red]

Leaf temp being higher than air temp should not happen. There is typically a 2* drop in hid and 4 in led. If your leaves are hotter than the room you must have a big iR source radiantly heating them.

 

[goodbye95]

I have strong leds but they are at lowest intensity and in the heighest posibble place ( about 140 cm, and 10%intensity) 650watt

 

[goodbye95]

The leaf temp goes up to - 2 c after i water the plants and then rises again after 1 - 2 days , without being the time to water again .