So these are my Amnesia Haze seedlings. They broke ground on the 13th and started enjoying sunlight. For the past 3 days I have slowly been introducing them for a few hours twice a day into the tent under the lights. I have the lights relatively high, about 36" or so. Light night was their first overnight stay in the tent with the lights set to come on at 6am.
This is them BEFORE I went to bed
Plant 1
Plant 2
Plant 3
They all looked fine before I went to bed, and then this morning I noticed two of them had some proximal purpling of the second leaves 
Plant 1
Plant 2 (the one that looks the same)
Plant 3
Strain - Amnesia Haze Auto
Hydroponics / soil
System type? Current Culture / A Pot for Pot
PH of runoff or solution in reservoir? 6.3
What is strength of nutrient mix? None
Indoor or Outdoor- Indoor 2x4 Grow Tent
Light system, size? California Lightworks SolarSystem 550, 400 Watt Full Spectrum LED Grow Light
Temps; Day, Night 74-79 for day. 68-70 for night
Humidity; Day, Night- 49%
Ventilation system; Yes, 4 inch in line fan with 2 desk fans for additional circulation
AC, Humidifier, De-humidifier,- no
Co2; No
I need guidance. What could have caused this to happen? What can I do to remedy this?
