Planted on 8/12/18. Sprouted on 8/15/18. Initially light was 12-15" away, but I noticed a good bit of stretching so I put the lights on top of the top. Temp is in 80s due to no actual exhaust installed. Ambient is 73F. Using 1 Green Pad Jr. every 5 days removing the old after 10.
@Frog_Fisher,Promix is pretty neutral and doesn't really come with any nutrients in it since it's a soilless mix. Fox farm is typically pretty 'hot'. In regards to PPM my water is around 50ppm so 170 is actually pretty low in my experience and I was using a good bit of Co2 with the greed pad jrs.
If you watch his Great Root Race video you'll see the plants with the green pad actually yellow pretty quickly as they're absorbing nutrients at a faster rate than the other plants.
@bobo420, Updated pics yesterday. Last pic should show set of two true leaves. Even the first few pics do actually. Cotyledons are below that. If you mean :they don't have 5 leaves" that's a size thing. Technically there's no difference between how the leaves function/show symptoms once true leaves start appearing. Only the cotyledons function differently.
EDIT: Besides, yellowing is from a lack of nutrients and the plant pulling the nutes from the leaves. It's entirely possible for any leaf to yellow if the plant doesn't get what it needs from cotyledons/media. Whether the leaves are "proper" or not doesn't change how the plant gets nutrients.
@bobo420, That's why I mentioned my not getting yellowing yet. If I was (or had other signs of a deficiency) I'd totally agree that the 270ppm was too low.
EDIT: Also Co2 PPM levels with 2-3 green pads should be pretty good. The videos I've seen show that in a dome (when not venting obviously) PPM levels are around 600-700 per pad. Obviously that would be nothing if I was venting, but it's in a closed dome.
I have grown the raspberry cough from Nirvana they were great. Both plants stayed short and stout big indica leaves. Smelled great when they were done as well.