TripleBeam
Well-Known Member
Your issue is not light stress. Seen that before in my current grow. 36" is plenty high for cobs. Keep a minimum of 24" above the canopy in veg. I'm learning in flower that I can get away with them being closer than 24". If you have the ability to dim the cobs, turn them down to 50% in veg. I finally turned my cobs up to 100% from 80% at week Three of flower. If your using promix hp, the hp stands for high porosity. So it drains well. It won't hurt to add more drain holes to the pots to ensure they drain properly when watering. Like Mag7 said it, the roots are unhappy. I have noticed that once stress happens the leaves don't change much. You have to watch the new growth to see if you fixed the problem. The lower leaves on the left plant could be yellowing due to the plant digesting them to create new roots or new leaves because of soil conditions. Probably not soil activity issue due to being so early in the grow but it could be the soil temps are too low or the temperature of the water your using is too cold. Soil and water temps need to be in the upper 70s as well. I store my water in my tent to ensure proper temps. What type of water are you using?Ok, 36" should be sufficient from what everyone talked about but tripleBeam would know better than me. What % are they set at? Tent or room? What temps, also, sometimes it is as simple as overwatering. Overwatering is the initial issue and everything follows after, fix the the issue and everything else falls in line
What I would do is check bottom soil temps. Ensure water temps are good. Add an extra day or two before watering again to ensure drought conditions. Do a de-stress foliar spray per instructions. Don't add anything to water when watering until 5 leaves AND at least five nodes. Watch the new growth to see if conditions improve. Environment first! I'm sure the more experienced growers will chime in soon.