i had this new seedling directly under a 400 watt ...

Hi @khushalkhan31! Pretty simple: HPS are not made for small seedlings, and 400w is way too much for the first days of the plant. Using a 400w HPS on small babies will result in heat stress & light stress. Hope this will help, let me know in the comments section if you need any further information. Happy growing! 👊

Yes that's a sign of heat stress. I forgot to metion u never what to change anything dramaticallyvin environment. When u where at 3 ft I would of start to lower light a inch a day at most til I reached 2 ft or where u fill comfortable. Don't worry back light to 30 32 inches and start there. She will bounce back no time.

Well , its to early to see if she gets any damage or not. but 2-3 feet distance sounds good to me. Iam using very small lights for my seedlings ( 2x26 watt Led) those small lights i can put quite close on my seedling without hurting them , Because the Led is quite cold. For later you have to find out the right distance for the girl and your light. If you are to close your girl is " dwarfing" under the Light , grows very dense with a small internodial diatance. If you are to far away your girl stretches and has a biig internodial distance. So first grow is alittle challenging. You havent made it easy to yourself, in growing in a unknown envoirement, and using coco.... to it will be a very educational grow... Stay strong.. and for further questions just ask

IMO - you’re simply too early in the game to be noticing any significant issues with the plant. From what I can tell of the one photo, her first true leaves are only just starting to come out so the curling is actually just the leaves starting to spread as they get larger. This isn’t an issue and based on what you’ve done with the medium prior to planting you should have no problems at this point. Only one little tip - it’s great to pre-flush your medium prior to planting but any benefits you’d derive from pre-loading itwith calmag will be lost if you continue to flush after this. Ultimately - just continue to supplement calmag as part of your feeding schedule as you move through each week of growth and everything should be fine. Hope it helps homie!👍👊