Week 5 auto flower new growth lime green and new growth tips yellowing (but not burnt)

Hey Guys what's going on!

My phone is not on me right now to upload a pic(Will do soon). But the gist of the situation is my Buddha Purple Kush auto was motoring along till week 5 absolutely flawlessly then suddenly the new growth tips started to show what appears to be yellowing. The new leaves themselves look lime green.

was previously feeding Canna COCO a+b @ 500ppms with 80ppms of calmag. Today I reduced feed to 300ppm and upped calmag to 100ppm.

What do you guys think?


My setup -

PH is 5.8
Medium - Coco Coir
Frequent fertigation drain to waste setup

Forgot to mention - There is no burning or any kind of damage anywhere else on the plant other than the new growth and 1 or 2 lower most fan leaves yellowing (not burning).