Yellow Leaves Spreading Quickly

PH is 7.0, Foxfarm OF medium, 400w HPS, and temps are 72-82. 3 weeks into flowering.

I thought I nute burned them 2 weeks ago (I did to two before I caught myself) and severely backed off feeding them (hardly at all the last two weeks). Am I under furting them now?

Have more pics if needed.

PIC 1

PIC 2

Give it a lil N, but don't overdo it.

oh yeah shes hungry for N. usually if i burn a plant i will flush with a 1/4 strength nute mix instead of straight H2O. when you flush her you should give her at least some nutes or else she will starve

Nothing that shouldn't be taken care of by a feeding. Just some N def.

I did a half a dose of all three foxfarm furts (big bloom, grow big, tiger) last night, didn't see drastic improvement, but it didn't get worse either...should I feed again at the next feeding, half does?

Could anything else cause this?

thanks for all the answers people...

big bloom and grow big have such a low npk. but the tiger bloom has 2-8-4 npk which isn't ideal at all, but this will work i guess. you should really pick up some nutes that are balanced like jacks classic 20-20-20 or miracle grow tomato food 18-18-21, or one of my favorites shlutz rose food 18-24-24. i would use any of those nutes listed at half strength and feed every other watering.

you should try and use something in the ball park range of 10-10-10 every other watering, and by using the nutes listed at half strength you can achieve this.