hey the first thing you must do is seperate them as carefully as you can. you dont want more than one plant per pot. it shouldnt be to hard as they are small. get them as much light as possible you need more sun. at three weeks it should be a bit bigger. but its healthy looking so it can pull through and be big yet. so transplant in their own containers. as much sun as possible, and get them a very light dose of nitrogen fertilizer about 1/4 strenght to start, then follow the directions. and dont let then dry out but also do not overwater either.