yeah, they'll need food soon, but keep it light, i've never had an auto of any kind like over 200 ppm...if you're trying to stay away from synthetic nutes, i'd get some kelp meal, some alfalfa meal, and some bonemeal. 2 parts alfalfa, 2 parts kelp, one part bone meal. and one part epsom salts. mix all that together, and top dress about 1/4 cup into each plant the next time you water. then i'd add a couple of tablespoons every other time you watered.