Yellowing leaves during flowering

Hey guys, here are the specs:
1m x 1m grow space
400W HPS
Soil
Nutrient solution once a week- Nitrogen 8.7% Phosphorous 4,4% Potassium 7,7% Magnesium 1%
Water ph’ed at 6.6
In flowering for 2.5 weeks
Pictures are attached.

The lower leaves are yellowing and will son die out I fear.. I know this may be a response from the plant sending nutrients to the buds and sacrificing the lower leaves, but I want to be safe The one on the first pictures is very bushy so the undergrowth may also be deprived of light and start to wither, this one has more yellowing leaves than the other, growing more vertically. I also read this could be some nutrient deficiency and that’s why I listed the nutes. What do you think guys? I don’t want to mess up my yield. Thanks in advance

Lol I used to think that was N def aswell, 8.7 N is way too fucking high for flower , looks like some N toxicity with the dark green tips clawing, crumpled curled in yellowing looks like typical phos def which makes sense, ph to 6.5 why 6.6, the ratio of 6-4-4 for Fox farm grow big (veg) and 2-8-4 tiger (f) is a nice rough estimate of how n goes down as phos goes up in flower, I rarely need to add N during flower, also NEVER panick feed trying to protect the leaves falling off, they're going to fall fuck them,the spike in N won't save even N def leaves but will surely damage healthy leaves and make the buds fluffier, also if any buds are shrivel ing in the shade pluck em freeze em then make hash- leaving them keeps the buds with direct light and air flow not get the nutes, I figure if I pick 20 baby buds weighing a gram, the buds weighing a gram have all that dispersed energy focused on big buds= more better quality

The accompanying pic is more the typical plant sending nutrients to buds look with yellowing fan leaves........you have a different problem.........

Lol I'd love to see you burn that plant

What problem do you guys think I have ? should I change nutes then ??