just turn down the light!  if the intensity of the light if its too high growth will be slow! nutrients are not going to make those plants fill the screen. I take it what I said in the other post is not what you wanted to hear...can you check the ppfd? there is an app for your phone so you can check it...

if you fill the screen before flower this is what you will get...

Just trying to help...keep you mind open...be receptive to answer for your questions...