Fan leaf stems purple / Possible pH issue?

Hey guys.. About a week ago I noticed quite a few of the fan leave and budding stems (Tech term for these?) starting to go completely purple.. I read up and found out it could be MG def so I upped my cal-mag dose and have now noticed the stems returning to green for the most part. So anyhow I think i've started to fix the issue but also I tested the run off of several of my plants and i'm showing them i'n the 6.6-7.0 range. I know this is high, everything looks healthy and no other real signs of deficiencies. Since the PH is high and I don't want to run into future problems i've been watering with a 6.1 solution to bring it down. Is there an easier or better way to get my PH down to an ideal range? Any help would be much appreciated

Here is a pic of one of the stems returning to green

Also, I was reading that yellowing of the leaves veins could also be a start to a deficiency.. I'm assuming this is due to the high PH and not a lack or over-use of nutrients. I'm growing in soil with great drainage and using recommended doses of general organics full line

rich, dark green veins with yellowing leaf tissue is usually a sign of Iron defficiency or chlorosis. chlorosis happens when a plant is not recieving enough light.

but remember if you are in the flowering stage then your plants leaves start to die off in order to push nutrients to your buds.....

how far into flowering are you?
almost near harvest time?

Ebb n Flo said:

but remember if you are in the flowering stage then your plants leaves start to die off in order to push nutrients to your buds.....

how far into flowering are you?
almost near harvest time?

Click to expand...

looks like he's week 4 or so.

If you are, most plants could use a small bump of some nitrogen and a feeding of bloom nutes around now

Thanks for the replies guys, I put these into flower on 05/31 so 27 days now.. Those pictures were taken with my lights on and an incandescent adjustment on my cam so I think the leaves appear a tad darker green than they really are. However you can see the yellowing in the leave veins, everything else looks super healthy and the buds are flourishing.. I just obviously am aiming for the best results so correcting a minor issue now would be ideal

Here is how one of my AK-48's looks right now:

theyre called petioles, dude.

the strain i grow has the same color petioles as the one in your picture. some of the veins yellow, and some continue to stay red, but theyre all heathy and cracking off. dont trip.

Appreciate it.. I realize different strains will all have different characteristics I, just like everyone else hates steps backwards so diagnosing anything early I feel is best. I figured they looked fine the high pH bothered me so i'm lowering it some and hopefully that might help even more. Thanks