Super Lemon Haze day 5 12/12 claw AND yellowing...WTF?!?!!?

A bit confused on this one, guys, hope someone can lend me some wisdom.

This Super Lemon Haze bush is about 30" tall and now in day 5 of flower. It's about 10-12" away from a 600" HPS, temp at the canopy 73-78, nighttime lows ~68.

This plant has some yellowing and necrosis on the lowest node fan leaves (she's pruned about 12" up from the bottom), but also some clawing at the top as if they're getting too much nitrogen. I watered with pure water instead of the Fox Farm nutrients I've been using, 1 gallon of pH 6.5 through the #3 Smart Pot to get a significant runoff, just to be on the safe side moving forward.

Can someone help me understand what these two seemingly paradoxical symptoms may mean?

aww super lemon haze man the bomb!! try flush soil maybe salts build up not sure tho hope it'll be all right

What kind of soil are you using?

Having exact same problem with the same specs. Tops look over fertilized and lower leaves yellowing and necrotic. I have started to fertilize every 3rd watering at half strength. This helps.

gotigers0420 said:

What kind of soil are you using?

Click to expand...

2:1 ratio of Fox Farm Ocean Forest to Light Warrior.

I believe that the leech/thorough watering is already helping as some of the top growth is still clawed but some is emerging with a more healthful appearance. Still need to get to the bottom of this so I can avoid too more leaves going yellow as flowering progresses . . . anyone got any other ideas/potential causes?

Here are some new photos. The first ones were from October 31, these from November 6, so 7 days later.

The original yellow leaves browned and got crispy, so I pinched them off. I have now lost all the fan leaves on that first node, and the next ones up are starting to show a slightly different kind of problem:

I've heard nitrogen def. can cause symtpoms like this. I'm a newb, maybe this will help you.

http://www.420magazine.com/forums/problems-pests-disease-control/81275-cannabis-plant-pest-problem-solver-pictorial.html

Magnesium def?
I found this helpful. Newbie...hope this helps.
http://planetganja.com/viewtopic.php?f=41&t=2740&p=45632&hilit=yellow+between+veins&sid=ced40f4c2624fcd174e076564d6efa44#p45632
Epsom salts.
Curious what experienced folks say.