is this K or N deficiency?

I flushed but it made things worse.
Soil grow, 25c/50hum, biobizz all mix & worm castings 300w QB. The only fert I used was megacrop every watering, never exceeding 1.4.
The bigger one is 5-6 weeks into flower, the others 2 less. I thought it was N deficiency but now am leaning toward K.
I have a bottle of canna Nitrogen and one of pk13.. not sure which one will stop the yellowing from reaching the buds..

Aww man. This is exactly what happened but not quite as severely to my last grow. I ended up hacking some early before the brown got to my buds.

I never figured it out.
Mine started going yellow in week 5 of bloom, so I hit with a little bit of nitrogen. I flushed as well... Both seemed to make it worse.

Hopefully someone with some knowledge will let us know the error.

Good thing is...premature cut bud gets you a really heady, short lived high. Some of the best was from the stuff I cut early.

Hmm.. if N didn't help then I'm gonna PK it.. for me it started at the end of veg. I was sure it was N back then..

on 3rd thought it looks like some of it might be from the lights.. I had lowered them recently..
I'm going to dial them back to 250w and raise them 2".

Flowering plants don't use nearly as much nitrogen as they do while in veg. How far were your lights away before moving them?

whats the PH of your soil?

botman said:

I flushed but it made things worse.
Soil grow, 25c/50hum, biobizz all mix & worm castings 300w QB. The only fert I used was megacrop every watering, never exceeding 1.4.
The bigger one is 5-6 weeks into flower, the others 2 less. I thought it was N deficiency but now am leaning toward K.
I have a bottle of canna Nitrogen and one of pk13.. not sure which one will stop the yellowing from reaching the buds..

Click to expand...

its burnt from over ferts . maybe you had the light too close who knows



ride it out nothing you can do fix anything now.

botman said:

I flushed but it made things worse.
Soil grow, 25c/50hum, biobizz all mix & worm castings 300w QB. The only fert I used was megacrop every watering, never exceeding 1.4.
The bigger one is 5-6 weeks into flower, the others 2 less. I thought it was N deficiency but now am leaning toward K.
I have a bottle of canna Nitrogen and one of pk13.. not sure which one will stop the yellowing from reaching the buds..

Click to expand...

Whoa botman...don't add anything else till you know what's going on. My personal reaction is that you are using too much stuff. Soil has nutrients plus castings and 700 ppm feedings. You have multiple deficiencies and burnt leaves.

Just use water...maybe a little superthrive...and get it on a good wet dry cycle.
JD

lights were about 25cm away 4 qb132v2's at 300w... now 35cm and 240w.
The ph is ok as far as I can tell, I water with 6.5.

I already watered the more mature one with mild pk13 cause flushing didn't help.. maybe i just didn't wait long enough before feeding again.
I'll lay off completely on the younger ones and we'll see...
Thanks for the tips.