First grow - 2x RQS Northern Lights Auto

So, long time no see! Past weeks have not been easy, fixing Calcium/Magnesium problems and now dealing with early Nitrogen deficiency... Some leaves are already falling off both plants, soft stems, yellow/brown-ish color and crispy dry feel. Good thing is only lower small-medium leaves were affected, big fan leaves are still there (almost no light, but still there). I've been collecting 3-6 leaves from each plant every day, at the same time, we're a bit behind on bud formation, so my guess is that this Nitrogen deficiency (which is completely normal on late flowering stages) came a bit early than expected. Also, burnt tips on almost all leaves from Lady #2, nutrient burn. So, for the start of week 8 I'm changing a little bit my feeding schedule, increasing Nitrogen levels (bumped FloraGro from 0.2ml/L to 0.33ml/L, bumped FloraMicro from 0.8ml/L to 1ml/L). We're on a nutrient burn, so I need to lower my EC right now! I'm targeting EC for week 8 at 1.2~1.35 range, so I'll decrease Cal-Mag (from 1.5ml/L to 1ml/L) and reduce PK until plant is past nutrient burn (reduced FloraBloom from 2ml/L to 1.5ml/L). For her last feed during week 7, after managing pH to 5.9, I ended up with EC levels at 1.25mS/cm. A couple of growers suggested me giving them Silica (Armor Si, etc) and some PK booster (Liquid KoolBloom) during weeks 8 and 9, any suggestions on this? Which PK Booster and Silica should I use?