New start with Mephisto!

Day 8, I remove the plastic glass, I think there's anough humidity in the air of the tent but not to much to avoid damping off on the stems. I also put I little bit of voodoo juice 2ml/L in my sprayer, Temp 25 C, Humidity 70%, VPD 0,62 Kpa, TDS 150 PPM, PH 5,8. Day 11, some point of the leaf (cothyledon) are burn ? Still watering with voodoo juice and canna start. Temp 25 C, Humidity 80%, VPD 0,62 Kpa, TDS 150 PPM, PH 5,8.