I had seedlings on my windowsill for about a week and they have been outside now for almost a week. They have 6 leaves at the moment. Would it be a good time for nutrients or wait longer? thanks.
You can start feeding when it gets its 3rd to 4th set of true leaves feeding a low 1/4 strength feed and slowly building it up.
If you have good soil you can do without food for at least a couple more weeks, let the root systems get bigger and start slow so as not to burn them...I just gave my clones a first fat pinch of mexican bat guano yesterday, they are still in solo cups and all about 6-12in tall, most with 7-9 nodes. I wont give them more food til 2-3 weeks after final transplant...