Is this a potassium deficiency??

Hi growers, I'm undertaking an outdoor grow in South Eastern Australia.

The Strain is Barneys Farm CBD Blue Shark (Indica dom) and she's in the 3rd week of flowering.
Growing medium: Organic soil (mix of worm casings, mushroom compost, organic soil, sand, perlite)
Feeding: Water with compost tea and Charlie Carp (10.2.6) when required. A week prior to flowering I reduced the Charlie Carp and began weekly feeds of Manutec Liquid Potash (0.2.14).
PH around 6.2.
Height is short of one metre (approx 3 foot). Pot size around 15 litres (4 gallon)

Pictures show the story with problems arising after flowering begun.
Curling under of leaves and their tips. Necrosis mainly but not exclusively to older fans. Affected leaves break away from the stem/branch easily. Plant with minor chlorosis (leaves were greener weeks back). Bud sites appear healthy. My research points to a K deficiency.

I've never grown an Indica dom plant before and i understand they need plenty of K due to their faster flowering stage.
I'm also growing a Malawi Sativa under same feeding/watering which has just begun flowering. No problems with her.

Any help with confirming my fears and solution to reversing it? eg.Increase Liquid Potash??

Thanks

after flowering is initiated my girls show the same sometimes depending on strain.
my solution...I cut those unsightly leaves away and never look back. I'd use charlie carp more
and worm castings too, all the way till a couple weeks before finish. nice shape good look!!

Looks like a potassium def. and that plant sure looks like a sativa with those long skinny leaves, Indica typically has fatter leaves like mine

tpc_mikey said:

Looks like a potassium def. and that plant sure looks like a sativa with those long skinny leaves, Indica typically has fatter leaves like mineView attachment 3900474

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I think the leaves inward cupping from the deficiency make the fingers appear a bit skinnier than they should, but yep I hear ya. They're not like a typical Indica.
I'm also growing a Malawi with seeds sourced from the same seedbank and the leaves look nothing like a pure Sativa.

All the Seeds were received removed from their breeders packs under the guise of "stealth shipping". Dodgy!!

your plants are still using alot of vegging nutes 3 weeks into the flowering stage, infact thats when they use it up the fastest, as the first 3 weeks are the second vegative stage, so you have been starving your plants of N for 4 weeks, your plants also look over watered
your also ph ing too low you should ph at around 6.8
back off the flowering nutes for aweek give them some N and some MG

are they dead yet

If anything, you've probably poisoned them with too much potassium. You're giving a lot of potassium. Dosing once in a great while in good soil might be one thing, but giving that much every week in a potted planter might be way too much. That stuff will stick around for a while, so how frequently you feed is just as important as how much you feed in a single dose because it will build up over time and poison your plant. I think I would just let it be and see what happens.

polishpollack said:

If anything, you've probably poisoned them with too much potassium. You're giving a lot of potassium. Dosing once in a great while in good soil might be one thing, but giving that much every week in a potted planter might be way too much. That stuff will stick around for a while, so how frequently you feed is just as important as how much you feed in a single dose because it will build up over time and poison your plant. I think I would just let it be and see what happens.

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no shit lol