High EC, low runoff – Ca/Mg lockout with AN pH Perfect in flower

N deficiency.. not Ca or Mg .. those are two different things with different symptoms and different pH where it impedes availability. Completely different things. think your water tests are not accurate. If there was no calcium it'd have rust spots all over the place... and if no Mg, it'd have interveinal chlorosis with necrotic spots accompanying it.. but those symptoms would be delayed from the point at which the physical deficiency started (4-6 weeks later). There's no way your plant has been deprived of Ca and Mg to such a degree. Seems like a high dose, too. EC is important, but it only moderately correlates to actually ppm concentration of the nutrients. Caclulating ppm from the gauranteed analysis labels would tell you a lot more. ppms 120-130 N 40-60 P 180-200 K 100+ Ca 75-80 Mg 100ish S This would be a safe starting point around 650 PPM. On a device using the "500-scale" it'd should read ~1.3EC. if it's a 700 scale, it'd be .92EC... you can see the brand impacts conversion factor for no reason other than whimsy... this is why ppm calculated from gauranteed analysis percent of mass is far superior information to work with.. plus, you see per nutrient concentration. overall concentration does not tell you much.

I won’t be able to tell why the runoff is so low. I never seen that before. Even with a heavy feeder cultivar, it doesn’t absorb so much in a week. All what I can tell is about G/M/B, it makes a 4-3-8 this ratio is more a Flowering nutrient, 15 in total isn’t a high concentration. 4% of Nitrogen is a bit low in my opinion, particularly to support a cannabis plant stretching. I would recommend between 8% to 12% Nitrogen for Vegetative cycle and the first 3 weeks of Flowering cycle, in total the concentration will be much higher.