I think i Kept the seedling too much time in the shade and in the peat pellet , now repotted in 9,5 lt antispiralization pots with BIoBizz ALLMIX and Perlite, and started watering with ph 6 tap water and 1mg /lt of root enhancer RHYZO1200, seem to respond very well, others too.
About 0,3 lt watering each other day.
Sunny and hot. (25C) june