Potassium lockout?

Badmofo529

In Bloom
I've been trying to fix this plant for two weeks now and I'm at my wit's end with it. Pretty close to just yeeting it out of the tent at this point.

Everything else is doing great, but this black banana cookies is just getting worse and worse. Only thing I can think of is a potassium lockout from low pH, but it's been getting the exact same feed (Jack's 3.6-2.4-1.5) @ 6.2-6.4 (promix hp) as everything else.

It's growing pretty slow, and the new growth looks fine for about a day and then ends up like this.

If anyone has any suggestions for me I'm all ears.

IMG_20200604_125330~2.jpg
 

Badmofo529

In Bloom
I typically don't mess with checking runoff since it's a huge pain in the ass, but I might try next watering. It's pretty much everywhere on the plant. It popped up after a one time feed at 5.9 pH and I thought I had corrected it since the new growth looked ok for a few days, then I did a big defoilation/lollipop and flipped to flower. Now it's back to looking like this.


Now I'm wondering if the extra calcium from the Olympus up may have played a part in locking out the potassium...
 

Deebs

The Sentient Naturewalker
Staff member
Administrator
Moderator
Here is a good thread where @JL2G was diagnosing an issue with his alter bread lady.

Not sure how it turned out in the end, but a slurry test was done, showing high K. If pH came under 6.2 I would have leaned toward calcium lockout....in that case the stems and roots may show deficiencies. There is much more in that discussion to think about!
 

Badmofo529

In Bloom
aquaman threw this up, the other day. u have a better understanding of it. I'll memorize it, when iii am no longer my problem.
I was looking at a similar chart a bit ago, and that's what made me wonder about an abundance of calcium antagonizing the potassium.


I don't have any way of checking for anything other than pH at the moment, bit a 75% feed with a bunch of runoff should make sure there isn't a buildup of anything (in theory lol).
 

Badmofo529

In Bloom
Alright, dropped the Jack's down to 3-2-1.5 and ran a bunch extra through the BBC. pH in @6.3 run off @ 6.1. the others ran off @6.3-6.5. looks to me like the lime in the promix kinda ran out and stopped buffering that one and I pushed the rootzone slightly acidic and it hasn't bounced back.

If it doesn't look better by the next feed, I might skip using the r/o so I can feed @6.5-6.6 without using a shitload of pH up to try and get it back in line.
 
I think your on the right track, I'd do heavy waterings with even more dilute mixture 50% about, and definitely measure the runoff ppms, that should show you exactly what's going on, if it's sky high that could very well be your problem, could also just flush hard with phd water, then feed at 50% the next watering and slowly work up if the plant improves, should correct the EC and pH at the same time if you go that route, just my 2 cents
 

Badmofo529

In Bloom
I think your on the right track, I'd do heavy waterings with even more dilute mixture 50% about, and definitely measure the runoff ppms, that should show you exactly what's going on, if it's sky high that could very well be your problem, could also just flush hard with phd water, then feed at 50% the next watering and slowly work up if the plant improves, should correct the EC and pH at the same time if you go that route, just my 2 cents
I've been meaning to pick up a ppm meter for a long time and just haven't. I'll grab one from they hydro shop tomorrow if there not hella overpriced.
 
The one I've been using for 4 years now was 20 on amazon, only had to change the battery once since purchase lol brand was vanktool I think, it's lime green, and is definitely worth it makes things like this a non issue honestly gotta have a starting point to know what direction to go is my thinking, but some do just wing it with awesome results ??? dam old people ???????
 

JL2G

Jesse Loves 2 Grow
Staff member
Moderator
Q-36 Space Modulator
Here is a good thread where @JL2G was diagnosing an issue with his alter bread lady.

Not sure how it turned out in the end, but a slurry test was done, showing high K. If pH came under 6.2 I would have leaned toward calcium lockout....in that case the stems and roots may show deficiencies. There is much more in that discussion to think about!
I need to update that thread. Lol.

From what I discerned about my own issue, it was a K tox, and P def I was dealing with. The K tox was causing Ca and micro defs on me, and P def throwing it's own mystery in there.
I eliminated the potassium silicate, top dressed them with 0-7-0 bat poop, and added cal mag to their waterings.
They're on the mend now, recovering quickly from my own caused issue. Lol.
 

Badmofo529

In Bloom
Yeah I probably shouldn't have switched from tap to r/o AND my nutrient line a week before flip lol.

I usually end up with one plant per cycle that doesn't want to cooperate. if it comes down to it, I took double the amount of clones I need, so ill yank it and toss like 4 of the extras in 1 gallons and let them rip with the big ladies to fill that space.
 
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