with nute lock i flush for three days i tend to introduce calcium magnesium in a small amount, and vitamin b12 (one vitamin pill dissolved in a gallon of water) is cheap as a pill the stuff for plants is basically the same just $$$. But what I see are plants that do have nice color, trich production is happening apparently and though I don't know when they started or genetic preponderancy of your strain it seems like you have what, three weeks? Five? some ph strips will run you four bucks tops, go with that, simple is better right now, flush that final week , dry and cure it like a champ and enjoy. Your next grow will be that much better as you figure your system out and what plants you like the most. Lol the biggest threat to a plant is usually us so no worries just enjoy the process. Good luck.