Third week.
A rather boring week, since TOPing the plant took most of the week to really take off; but all the new growth looks great, no sign of nute burn.
At day 20, I fed again, with a stronger dose (1.2 EC).
At the start of next week, I will change to the 100 watt@2700K light and will soon pick the three stronger shoots of each plant.
@Fast_Buds, I made a mistake when uploading the photos; from week 4 onward I confused the strain with another one. This is now solved and makes sense, since the Crystal Meth is the only one that could have the purplish / black colored buds.