light => 400w MH/HPS (MH for right now because it's the growth)
temperature => is about 75-80F
humidity => 50-60%
age of the plants => I don't really know but they are 24" height
ph => I didn't received my ph meter...
nutrients => for right now I'm using Optimum-Hydroponix 2-part formula for the growth stage with Supermax B1, but I orded General Hydroponics flora-gro, flora-micro, flora-bloom and Superthrive
I also have a 16" oscillating fan running 18hrs/day (when the light is on) and 2 computer fan, running 24hrs, that's bring air from a exterior wall into my closet. And the both are in a round pot of 12".
20", it is possible that they are under watered ?? I tranplant it in the 12" pot yesterday... and I put like 500ml of water and when I saw the leafs drop I added 3L of water