It’s amazing how short this plan is I don’t think you’re going to get much of a yield though. I can’t give you much advice on the nutrients because I cannot see how much you’re adding per gallon.
You should be on a 12 hour cycle the 18 hours is not necessarily helping anything but wasting energy I find that more of the magic happens in darkness. Depending on if you’re just using your bloom mode on light you are definitely too far away and should bring it a little bit closer maybe 24 inches from top