Hi Ive noticed yellowing of older leaves. Is this...

I would flush (water with just plain phd water) for the last week or 10 days. yellowing is not something to worry about in the last period before harvesting if that is not related to nutes or ph. looking good buddy keep on going!

So towards the middle end of flowering, you're plants aren't just taking from your root zone, they literally drain nutrients from the older leaves, this is why it can look similar to nitrogen deficiency. For your next grow, flushing occasional throughout should help with lockout or buildup, and potentially ph runoff being so high. There are some supplements that do help with this process like Foxfarm sledgehammer. If you're flowering weren't very close to finishing then an over abundance of yellowed leaves may be a bit more problematic. Did you know the estimated growth or "flowering" time for this strain? Also as stick said, definitely give some plain old water not just nutrients always. And definitely flush or you'll wind up with some funny tastes and smells occasionally.

Hi bro, first of all, lovely backyard you have there! Yellowing is completely normal during the flushing process : plants will absorb every nutrients they can, to produce heavy flowers. But I see you're not flushing yet, so this may be a nutrients issue. Do you give them plain PHed water between nutrients meals? Or do you give them nutrients every time you water them? Your runoff PH being higher than your input PH is a clue about overfeeding for the last weeks, you may have some nutrients accumulation somewhere into your containers. I'd recommend to flush them for 2-3 days with plain PHed water (6.2 - 6.4) and see what happens. Finally, I see you moved your plants in different environments (in/out..), this may have generated a stress / lockout. I'll be around, good luck with these outdoor beauties!