Its too soon for nutes. Wait another week and then use a very mild dose. Like 1/4 strenght tops. I would find something closer to the recomended NPK but that will work to start. Its best to fert then water only the next time till a little comes out the bottom to leach out the old ferts. Peters fertilizer is 20-20-20 and very good for veg. The 20-20-20 just means the % is twice that of the 10-10-10. The recomended NPK for pot in veg is 10-10-10 and 10-30-20 for flower. Good luck with your grow. Peace Out!