I'm a bit concerned for my LSD as the leaves ...

hey there Manabu, so two things are happening, dark green leaves is a nitrogen excess and the brown spot on the leaf with the purple stems that means calcium deficiency. what i'm guessing happened is that because of slight over watering the plant got too much N after the defoliation and then it started to look for more calcium to build more leaves and grow their stems. That's fine, very minor and very fixable problems. So just cut down on the watering just a little bit and go back to a strict wet dry cycle as well. For the calcium deficiency you should do a foliar spray. use 1ml/L floramicro in a spray bottle spray close to the night time the leaves and underleaves every one or two days for one week and you should see improvements within 5 to 10 days. Hope this helps ! 🚀