Feeding

Bluntzilla has it right. Be careful not to over water as well. This will stunt seedlings. I water a little and often when they are so young. My personal rule is to not water too far past the spread of the leaves themselves. It is only when the growth has stretched out beyond the edges of the pot that I water it right to the pot edge. The roots need air and a young plant can drown if you are not careful.

I'd only add that some of the answer will depend on what kind of soil you're growing in. Right now I'm growing in Fox Farms Coco Loco which starts out pretty nutrient rich on its own. I didn't start using the Fox Farms nutrient trio (at half strength) until around 6 weeks, at which point the plants were already over 2 feet tall and healthy as hell. On the other hand, I have another batch of plants growing in a mix I made that is 1/3 coco coir, 1/3 perlite, and 1/3 various big box store garden center bagged soil. At around 5 weeks I started fertilizing them - they were only about a foot tall and kind of scraggly - in hind sight I'd say I waited too long to start them on nutrients. Hope that helps and good luck with your grow!

About 10 to 14 days after sprouted I introduce nutrition but just a light taste first time. Good luck and happy growing 🌲🌲🌲👊

The best thing you could ever do for yourself is get an EC meter. You should be between 400-600ppms right now (probably the lower end). I would start off at quarter strength for at least the next few feeds. Then increase it to 50% after.

Well technically you need to fertilize when the roots have absorbed most of the available nutrients in the medium but this usually leads to slight deficiencies that can be avoided. I personally like to start fertilize when the second set of leaves have matured (3rd node starts to grow) with about 1/5-1/4 of the recommended dosage to avoid those deficiencies. Remember to always use 50% at most of recommended fertilizer dosage to avoid toxicities completely! deficiencies are much easier to identify, deal with, and easier on your plant. Hope this helps! Good luck and happy growing :)