Is this a nutrient deficiency?

Hey all, I have a 27 day old AK-47 growing in a DWC bucket. I think i have stunted her growth a couple times. Once by having too high pH and then over feeding her (lucas formula).

Anyways I noticed the bottom leaves edges are curling up. Should i feed her more? Currently i am only giving her 1/4 strength. And a little scared to give her more. You can see what happened to a couple of the leaves last time!

Also when is a good time to start flowering? Thanks!

Young, established seedlings or rooted cuttings are started at 500-600ppm. The TDS is increased to 800-900ppm during peak vegetative growth. During the transition from early to heavy flowering, TDS is further raised to 1000-1100ppm. It is then reduced to 400-500ppm during the final 2 weeks of flushing. The plants demonstrate their preference for a lower TDS/EC when running a lower pH by clearly sustaining higher growth rates.

Keep the PPM low until the growth rate increases.