Yellow edges starting at top

Hey growers my buddies outdoor plant is got yellow edging that started from the very top fan leaves and is working its way down the plant slowly. Im pretty sure i know what it is but hes stubborn when he thinks he knows and swears its a K deficiency. I wont say what i think it is cuz if anyone agrees with me he say that there just jumping on the band wagon. So all u pros out there chime in plz

Oh ya and the top leaves are the only leaves effected all lower n mids are happy and healthy

Its getting worse working its way down from the top. Its not just the edges n tips its in the margins too and now theres brown spots like a p def. Some1 plz chime in here thanks

Very top cola

Dude, I think you need a new friend...

Definitely a k def

SCM 831 said:

Definitely a k def

Click to expand...

Ya? Ive never seen them start at the very top n work its way down but ive heard it b4, i checked his soil ph and it was on the low side about 6.1 most spots 5.9 in a few i was feeling more k lock out as it started rite after he top dressed with some bloom nutes