The plants are recovering very well from my initial wrong setup. After 20 days the tallest plant is 18cm and in general they look kinda healthy. At this time I got 400W at 50cm high 20/4off. Should I increase to 600W and/or put the reflector closer ?
I would switch to 600w when she starts to flower, but that is just me, ideally you want 7000-10000 lumens per sqft. There seems to be a bit of stretching in one of them, I believe that if the temperatures are fine you could lower your lights a bit, other than that everything seems fine to me! Good luck!!
the tent is 4x4' and the light at 400W has 40000 so based on your 7000-10000 lumens , I think the light is ok. temperature right now I manage to keep it 26 celsius and humidity 46, that I think is too low.
Yes I seems fine indeed, lower the lights see if the canopy keeps in the same temps. Check this too, I might give you new info: How Far Away Do I Keep Grow Lights From Cannabis Plants? | Grow Weed Easy I hope it helps!