hii people i am a first time grower and my leaves seem to be going yellow i have 2 400w lights i thought i was over watering so i backed off nw the watering fine they drinking good so thought it might of been underwatering bt they still yellow could thits hot is be room temperature 2 highs of 32degrees and lows of 28 degrees, plants are 3 weeks old, help please????? how do i upload pictures of them