Sup Guys. Been growing for little more than a year now. I have about 6 complete harvests under my be

Sup Guys. Been growing for little more than a year now. I have about 6 complete harvests under my belt. Now I didn't say successful harvests because in my opinion they were all okay. And I'm find with okay cause I'm patient and understand this is a process. But I'm Gaining no process if I dont figure out whats going on during flower. So here I am.

Set up:
Tent:4x4x7
Light:600 Watt hps
Exhaust:710 cfm Hyper fan

Grow:
5+ ft Afghan Kush about 4 wks in flower
Fox Farm Ocean Forest
PH'd tap water to 6.5 with ph tester. PH meter broke.
She only had water for the 2 months of her life.

Problem:
She Looking real frosty and smells great. even the colas are starting to form.
But all the fan leaves on the bottom half of the plant is yellowing and dying off.
I assume its time to feed her so I have big bloom and tiger bloom for her.
I tried feeding her less than half strength, shes still doing the same thing.
any suggetions? this happens all the time during flower.
Thanks

Pics in natural light will get you more answers

you need veg nutes N, if the fan leaves are going yellow at the bottom

Big Bloom and Tiger Bloom will only make things worse IMO.

It was time to feed her long ago. This is exactly what one could expect without feeding their plants. Also, in the future, look at training/bending/topping your plants so they aren't as tall...a 600 won't penetrate that deep.