Yellowing of bud sites

600w with 2.9umol/J efficacy... I'd use a meter to set height for best canopy coverge end-to-end without sacrificing overall average (measured at various points from same distance etc). Can even be a klux meter because this is about proportional intensity. This light can cover 21-22 sq ft at 100% power. If you are focusing that light on a smaller area, i'd drop the power in a proportional way or use a higher hanging distance that lowers overall average in proportional way but also gives greater intensity to sides/edges -- the latter choice costs more watts and is a bit more wasteful but would provide the best yield all other factors the same. Your vpd is in a good enough range, so it should be able to handle 37-38 DLI with ambient co2. This is just a good starting point and you use internode development as your guide to adjusting intensity from there. As far as what i see, there's not enough info. Chlorosis in new growth across canopy in flower often comes with p/k boosters. If you blasted it with elevated p/k lately, i'd say that is the cause. "full strength" means different things for nearly all fertilizer instructions. if in soilless/hydro context, a breakdown in elemental ppm per nutrient molecule would help diagnose. overall concentration doesn't tell us much when diagnosing a problem. Though EC looks high, this could be deceving... EC conversion to ppm is imprecise and inaccurate. Some soil ferts read higher because a good portion is not plant available, so what enters the plant is not the "2.4-2.6EC", it is lower. anyway look at a leaf symptom chart and you'll see the various options for chlorosis in new growth... how it progressed is relevant and can discern between causes. tip-in? petiole-out? etc.. is it starting between veins or just a solid trend all over? more than a couple trace elements will catch your eye and that would be rare. in those cases it's more likely ph or nute lockout.