Stain on the leaf

Bro, you can't put it under strong Sun right now! It doesn't even have 5 pairs of grown leaves yet! Strong Sun provokes an increase in the speed of photosynthesis in the plant, its tissues haven't grown yet, they're not ready to carry out such processes and will die if they stay under that stress for too long! It's too early for it to be under the Sun! Only after five pairs of grown and formed leaves! No other way! It's like making a six-year-old work in a quarry! He’ll get exhausted quickly and die from such work; he hasn't grown, hasn't become a physically strong and resilient person yet! It's the same with plants! You pushed it into too active work and it got exhausted. 👆 The points at the growth site indicate this, as this spot was illuminated the most and the same active processes were happening there as in the whole young plant. But this spot is still young itself; it's younger than everything else! Be careful with the plant! Read about lighting in the cultivation area; I'll write more about it later. 👇 You can measure the illumination (lux) in the cultivation area above the plant! Download a free app called "luxmeter" from the market on your smartphone, clean the screen side of your phone well, removing grease and dirt. The light sensor is located on the screen part, which often rivals individual lux meters. Check the illumination above the plant. Adjust the lamp height so it doesn't heat the plant to shock states but stays within the lux range. Install the app; you’ll remember me more than once, bro! It will be like a compass for you in terms of lighting! Effective illumination ranges, starting from the planting of the plant: Day 1 (250-500lux) Day 2 (500-1000lux) Day 3 (1000-2000lux) After five pairs of leaves, full vegetation (2000-20000lux) Flowering (20000-90000lux). Theoretically, the most optimal for flowering is considered to be (45000-65000lux). Try not to exceed 90000 lux. Otherwise – 100% problems due to too active processes happening in the plant! Good luck, bro! ✊😇