Tâches sur feuilles ??

Start with your light. That is very close, I would nearly double the distance. If they start stretching and getting lanky, the drop it little by little. If moving the light doesnt stop the spread, check your feed and runoff pH. You should only be feeding lightly right now, maybe 25% (up to 50%) of the manufacturer's instructions. It also may be time to transplant. Last thing is to make sure you're not getting the leaves wet. Water droplets will magnify the light which already very close. Hope this solves your problem!