I usually do not start feeding my plants until about 2 weeks and at that point I start off with a very diluted solution and then gradually build up.
I usually go for 1/4 the reccomended dose for at least a week, then 1/2 for another week, and so on.
BTW you should transplant those into each their own seperate containers soon. They have a tendency to intertwine roots and it will stunt their grow if you damage them.