Crispy, golden brown leaftips and no smell, help!

E-indoor
E-coco
E-CocoGrow Coir fiber
HCL-Regular 3 gal plastic pot
SCL-25% pearlite added
SCLR- about 6.1 Runoff pH
E-On-Site RO
E-7.0 PH
E-5 weeks veg, now 8 weeks bud
E-General Hydronponics Flora Nova system, Calmag, Koolbloom, Sweet
E-About 7 cups a day
E-600 watt HPS 20" away now
E-75-88 room temp
E-45-55% humidity
E-12/12 Lighting schedule
E-6" turbo fan + intake bathroom style fan

Hey, nice to meet you. I'm a new first time grower and I'm having a problem in late bud. The leaves are turning a into crispy golden-brown mess, with the tips starting first and curling under, then the margins. The Cheese unfortunately have got it the worst and they are the largest.

I've been pruning them as they get bad, so I don't know if it will kill the whole leaf or not. It's the first problem I've had, but thanks to the dead reckoner at 420mag I suspect it might beK or Manganese deficiency.

I mix 12 one gallon jugs and hand water with a measuring cup twice to three times a day, until water barely seeps from the drain holes. I lowered the ph from 5.8-6.0 to 5.5 to avoid K lock, and I removed the dry Koolbloom and raised the lights to reduce stress. The leaves feel dry, and the crystals on the leaves seem to have fallen off. The buds seem stunted and don't reek like they used to. I've put many hours into this and I don't want to see my babies turn to ragweed!

Thanks!

Hello athirdpath. I'm new to coco, first time grower as well (which I guess makes me new to everything, not just coco LOL), so I am learning a TON about it.
When was the last time you flushed?

Also...check the chart I've attached. Pay close attention to the right side of it...that's where you and I live. I water mine with 5.1 PH water, and let it drift up going through the whole spectrum. I'm not saying "DO THIS", I'm just saying that's what I've been doing and my plants are looking very nice being in the 7th week of flower.

*junk

you sed your using koolbloom? is that the 2-45- something? its a finishing product correct? if so cut you usual nutes down and flush right now.i just lost 6 plants because i was trying out koolbloom for the first time,this shit fries your leaves.