Nice man, those are looking huge for day 22... Hope you've got room cause the explosive growth stage is still coming
As for the leaves, if it's just the very bottom ones yellowing I wouldn't even worry about it... When I turn my autopots on at around 3 weeks I'm usually feeding 1.5ml/l cal-mag at that point. Doesn't look like you have a cal-mag deficiency tho... If it gets worse you may want to posts some pics in the infirmary section since I'm not very good at diagnosing problems Good luck with the rest of the grow.
Thanks mate, they're crazy.. 114 CM in height right now at day 32. Monster plants!
The yellowing at bottom never spread.
My only worry now is whether to switch to bloom nutes cuz they might hit the light lol (since they didnt stop growin vertically yet)