Youthmananswered grow question 2 years ago Ok ehm... All😱
But you are right, you are here to improve your skills!
So, first: under watered, one of them had the leaves down all over the vegetative stage, the other suffered on the roots (yellow leaves with red stems) for the same problem.
Remember that is better to have a soil always wet(without over watering) where roots can grow everywhere, watering when the first 1-2cm of soil dry
Second: temperature! 13 Celsius?too cold
they need at least 18-24 during vegetative, better 22-26, and during flower 16/18-20/24 depending on weeks and genetics.
Remember they are plants that grow from sea level to 2000m without problem.
And the fan, always on! Not directly on the plant the first 2-3 week.
For the next time try this:
Lamp at 30cm from canopy always if you can dimmable It, otherwise change height
18-24 good range
Pre fert soil (light mix) using only root juice first 2 week and One fert before flower (maybe more)
Fan always on, oscillating better
Soil always wet