Grape Ape - first cannabis garden

Day 43: This week she enters the ScrOG! I've brought the nutrient dose down to around 700 ppm. Still reading a low pH with each feed. I wonder if the runoff is lower than the actual medium? The water going in is usually about 6.3. Solution - pH 6.3, ppm 772. Runoff - pH 5.8, ppm 760. I am just letting her grow this week, although I am considering pruning her two lowest branches as they don't look like they're going to make it out from under the rest of the canopy. This may also help juice up the upper branching this week. Day 44: Today I took some time to plan out where the branches will be trained. I pruned off the bottom two branches with some really dull clippers (will replace) to try and boost the upper branches. I'm now working with 10 main branches all of which have good light. There appears to be the start of what I think may be a magnesium deficiency. I will try to amend the soil and raise the pH closer to 7 while also lowering the nighttime temperature to 68°F. I may try adding some magnesium sulphate with my rinse cycle, but I think the main issue is the low pH of the soil. Day 45: Watered from the tap. Solution - pH 7.4, ppm 80. Runoff - pH 6.0, ppm 810. The ppm was higher than the last feed. I'm going to keep upping the pH until the runoff is consistently 6.5. It seems that the auto-balancing nutrients aren't quite perfect... The plant is growing well but I am noticing some spotting on older leaves. Hoping this is not the start of powdery mildew. I am going to raise daytime temperature to 80° with night-time at 70°. The humidity has been rock solid around 50% r.h. so I will keep that rolling. I have some foliar spray that I will use if I become confident that the fungus is indeed present. Microscope on the way so I can take a closer look at these spots. I'm not totally convinced that there's an issue yet since I've been keeping the tent pretty clean and there is good air circulation. She's reaching up into the trellis and I've been able to wrangle a few branches, angling them to primo positions. The broken branch looks to have recuperated and is producing some healthy new growth. This will end up being the centre cola so I'm curious to see if she'll develop comparably to the other branches. Day 46: Just groovy. I think the lack of nutrient uptake may be result of a low pH. I will do a regular watering again in a couple days with high pH and low ppm. The root zone also needs to get good and dry between waterings. I'll hold off on the water tomorrow unless she looks real dry. Might do a foliar spray instead. Took the plant for her first haircut today! She looks great with the bottom 2/3rds cleaned up. Not bad for my first trim I think. I tried not to take too many leaves that were in direct light. Just giving the sub-branching room to grow up into the canopy and allowing better airflow throughout the plant. I was able to bend a few of the top branches towards their various corners and provide more light to the two lowest tips which I'm trying to coax towards the trellis. This is the first training that I feel confident I haven't done something terrible. Next grow I will top sooner and let the branches hit the trellis before worrying about doing much LST. Day 47: Adding some cal/mag to the mix today. Solution - pH 6.9, ppm 950. Runoff - pH 5.9, ppm 1070. I started adding some pH up with the fertilizer to bring the soil up above 6.0. The ppm was higher than I would have liked. We'll see how much she uses by the next watering. She has recovered well from the defoliation yesterday and now has room to breathe and grow.