What's this he asks.

[Waira]

mate, go to the colored section above this one and fill in that patient info form please, just c/p it into here and fill in,...
I'd say that's a micronutrient defc., likely a rare Mn defc. from those symptoms,... I also see signs of light/heat stress on those upper leaves, edge curling, yellowing compounded by the micro' defc.
An in-pot pH is also needed to make sure this isn't a lock-out issue because adding more nutes to an off pH pot will make matters worse! Hopefully this is a simple lack-of defc,. and you will need a good micronutrient supplement to deal with this, maybe a foliar feed or two with it in conjunction with soil treatment,... Earth Juice Microblast is my fav',....

 

[Micky&MalloryKnox]

I wanted to give this one a flush and just figured it should be water only. .

 

[Garage_Grower]

If you ever want to flush your coco to reduce its EC, here’s a simple guideline. Use nutrient solution that is at half your normal Inflow EC, Apply twice the normal quantity of water, Wait ten minutes following the application, Add additional dilute nutrient solution to produce new run-off for measure. Test the EC of this new run-off, it should be at or below your normal target inflow EC. If the EC is still high, repeat this process at the next opportunity to feed/water.


Easy smoking! [emoji869]

 

[Micky&MalloryKnox]

mate, go to the colored section above this one and fill in that patient info form please, just c/p it into here and fill in,...
I'd say that's a micronutrient defc., likely a rare Mn defc. from those symptoms,... I also see signs of light/heat stress on those upper leaves, edge curling, yellowing compounded by the micro' defc.
An in-pot pH is also needed to make sure this isn't a lock-out issue because adding more nutes to an off pH pot will make matters worse! Hopefully this is a simple lack-of defc,. and you will need a good micronutrient supplement to deal with this, maybe a foliar feed or two with it in conjunction with soil treatment,... Earth Juice Microblast is my fav',....

Apologies, I'm that guy that didn't read up on posting rules first. Noted for future