Purple stems to fan leaves

Okay i am on my 4th grow. Grow details below:

3 plants - Barney's Farm Strains 2x Liberty Haze 1x Chronic Thunder (was freebie)
Medium - FFOF Soil in 3 gallon Smart Pots; added dolomite lime at beginning of grow; little at beginning of flower; and more mid flower (today)
Nute and watering schedule - Lucas Formula (FloraNova Bloom 1 tsb per gallon) every other watering, plain water in between. Water is PHed to 6.5
Soil PH - Run off as of today was 6 put in 6.5. Run off seems to always be around .5 below what I put in.
Lights - 700w Mars II LED and 280w Blackstar LED - so about 400 true wats
Environment - 75 F @ 48% humidity lights on and 70 F @ 56 %
Age - I flipped 12/12 exactly 27 days ago

Perceived issue - This is not actually a problem to this specific grow. It is legit in EVERY single one of my grows. The stems of my fan leaves always turn purple.... Not right away they start off a lovely green then in flower they turn purple starting at bottom going to the top. My research shows it can be due to 3 things

1. Cold Temps
2. Phosp def
3. Strain

I know it is not cold temps, my last grow I was kinda lazy and didn't get the weight I wanted. I am not slacking I revamped my grow room and now check everything daily. The environment is regulated pretty well as you can see.

It could be phos def due to lock out, but the run off PH seemed okay. I always thought it was strain but given that it has been happening in every one of my grows I thought it was best to ask other people opinions. The yellowing of the lower growth on the chronic thunder has me leaning towards lockout. Maybe I need to calibrate my ph meter but did it like a month ago.

Will appreciate any feedback or comments (even if not about purple stems). Pics provided as well

Thanks

- Face

do you use r/o or distilled water?

chuck estevez said:

do you use r/o or distilled water?

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Neither, tap water left out >8 hours to let chlorine evap

like this ?????? if so is fairly common........

yeah, if it doesn't show any def. in your leaves, then it probably is genetic or temps. My plants next to my a/c always have those different pinks/purples

tekdc911 said:

like this ?????? if so is fairly common........

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yes basically, they start a nice green then eventually go purple. Only the stems. So it could be a coincidence that all of the strains I tried had this trait. I have only grown 12 strains so I know my sample size is not high and was likely confirmation bias lol

When people say it could be strain, there are no numbers to really tell you the likely hood. I thought was a rare trait not commen. Thanks for the replies.

- Face

I think your level of purple is pretty normal, a cold temp purple is quite a bit more colorful. Keep an eye on that leaf in the last pic to make sure those symptoms aren't spreading. It looks a little problematic, hopefully not.

Bugeye said:

I think your level of purple is pretty normal, a cold temp purple is quite a bit more colorful. Keep an eye on that leaf in the last pic to make sure those symptoms aren't spreading. It looks a little problematic, hopefully not.

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Yes absolutely, noticed it as well. Didn't change anything as if yet as didn't want to react to early (learned that lesson on grow 2). Right now the yellowing is only on the chronic thunder, so if it gets worse ill flush that plant, rebuffer soil. New growth looks good, so hope wont have too. I hate flushing. Thanks for your time and reply, much appreciated!

sadface said:

Yes absolutely, noticed it as well. Didn't change anything as if yet as didn't want to react to early (learned that lesson on grow 2). Right now the yellowing is only on the chronic thunder, so if it gets worse ill flush that plant, rebuffer soil. New growth looks good, so hope wont have too. I hate flushing. Thanks for your time and reply, much appreciated!

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Before you flush it, which I would not recommend, take a look at what broad mite damage looks like on cannabis plants. Not saying that is what you have but it would be something I would watch closely and examine under 60-100X magnification. They are tiny tiny little guys.

Otherwise, great looking grow!

Bugeye said:

Before you flush it, which I would not recommend, take a look at what broad mite damage looks like on cannabis plants. Not saying that is what you have but it would be something I would watch closely and examine under 60-100X magnification. They are tiny tiny little guys.

Otherwise, great looking grow!

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Thanks! gonna check right now.

When fan leaves become mature and ready to sacrifice themselves for the plant the stems often become purple, also if u bend the leaves around to tuck them away or out of the way of a bud site it can cause the stems to turn purple.

Genetics imo, ran some Platinum Bubba Kush that had those purple stems throughout the grow but no defs to speak of. Crossed that strain with Ace of Spades and Jack The Ripper, that trait came through in both crosses. Running 3 of them right now and only about 4 weeks from seed I can see the purple stems, yet the plants/leaves are super-healthy. Running 4 other strains in the same environment, same training/feed with no purple leaf stems. I tuck the leaves under some training rings I throw in early, only the crosses with the PBK genetics are purple though.