3 week on 12/12 no signs of flowering

They have been on ionic Bloom and 12/12 for 3 weeks and they just keep getting taller. There are no signs of flowering. Hydro setup, with 400w HPS. Space is a 2x3x5. Good ventilation. Plants went from 8 â?? 10 inches to 24- 30 in the past few weeks. Roots are looking good, no bugs. I also gave them a ½ teaspoon of thrive alive.

because there all males...lolj/k
you sound fine. give it more time is all i can really think of. its usually a few weeks before any hairs show