delicious sensi star traits

I popped 6 feminized sensi beans and came out with 7 plants lol (twins). Now I figured out early these girls dont like to eat but am searching for some characteristics sensi star has. They are 4 weeks old and under a 600 hps in coco, I feed them every 3 days with a ppm of 300-350 until the roots are more developed. Im growing vertical in flower with 2 600's and was wondering about the stretch since I like to fill out my room. Do these girls reach for the sky inflower or should I veg them longer, also what ec or ppm can they get up to? anything would help.