POTASSIUM DEFICIENCY?

[Massgrower98]

I've been told this is a potassium deficiency? At first I thought it was thrip damage, but then someone told me that potassium has a weird way of showing defecencies... I'm going to be feeding my plants tomorrow, top dressing with some bio live from down to earth and then a week from now I plan on using a compost tea so hopefully that'll boost the soil life so the plant stays healthy but i figure I'd come to the good ole rollitup page to get everyone's opinion on what it could be... the advice is much appreciated, I've only been growing for a year and a half so I'll def be on this page alot this year when I have a issue that is...

 

[Cannabis.Liberation.Army]

The fact that it's in the top growth makes me think it's a calcium deficiency. Potassium deficiency starts at the tips and the edges and looks like a brown or red burn. A lack of calcium weakens plant tissue and leaves it more susceptible to heat stress which is why it affects the leaves that are closer to the light source. I've had a similar issue in the past when using RO water without a calcium/magnesium supplement. I'm speaking strictly out of experience, so please wait until you hear from the others before you take my advice. Either way, please update us when you find a solution.

 

[Nutty sKunK]

Calcium deficiencies show themselves on the middle can leaves and cause dark dead rust spots.

That is simply bug damage. Either eaten now or when it was a younger leaf so when it grew out it enlarged the damage.

K deficiency is interveinal chlorosis on low leaves followed by burnt edges of said leaf.

 

[Cannabis.Liberation.Army]

Calcium deficiencies show themselves on the middle can leaves and cause dark dead rust spots.

That is simply bug damage. Either eaten now or when it was a younger leaf so when it grew out it enlarged the damage.

K deficiency is interveinal chlorosis on low leaves followed by burnt edges of said leaf.

That makes sense. Thanks for the clarification!