How far should I put 450w LED veg/bloom switches l...

Not that you don't need to figure out your lighting distance, but tbh your plant was likely just growing roots instead of vegetation. They do that, especially autos. Rule of thumb is usually 24-28" for veg for LED but that might be too close/far depending on your manufacturer.

Hey there, led is so unpredictable like everyone says, however most manufacturers give a recommendation for distance. Say if you got or go on Amazon and look up the light description it'll give you an inch recommendation. Typically I see 24 inches for vegetative, but seedlings are so sensitive that it might even need a little further. Or possibly give them little humidity domes on top for steamy protection. Starbucks makes many grower donations with their cold cups. :)

Take it easy, there's growth in those photos. I myself thought plants should be growing faster as a beginner. Patience is the grow word for beginners. LEDs are less intense (excluding LEDs with lens), heat wise, than their counterparts (Hid) so you can put them closer; 24-32 inches in veg and 12-18 inches in flower. Good luck!

A light of that power for a seedling is a bit of a waste but if it’s the only light you have I’d keep it as far away as you could Maybe even farther than what @ teflondonfarms recommended and go to 4 feet away as you can always move it closer later on as it gets stronger.

Unlike HID, there is no standard when it comes to LED's and plant distance. There is a huge range depending on plant age and LED power, that been between 30 and 60 cm. That been said, your seedlings don't look like they have heat stress (curled leaves) and for been 3 days old, they look fine. Be sure to let the soil dry between watering days. Also sometimes, seedlings have some trouble breaking out of the pellets. Give it a few days

Typically I keep mine at 30 inches when they’re a seedling. I’ll lower them gradually until they sit at 18 inches. Unless I see stretching then I’ll lower them a little faster than usual. Your 3 days in I wouldn’t stress about the growth just yet. She’s probably concentrating on getting that tap root down into the pot for a nice healthy rooting system. This is in my novice opinion and what I’ve found from my own personal experience. She looks healthy so far! Best of luck I’ll follow along!