Pink stems in flower. Please help

Hi. My plants stems are pink. I'm in flower. A little background.

Sealed room
Co2
Tall Boy to clean water / strip out sediment, chlorine.
9k lights
Temps 83
Feed with fox Farm adding
Cal Mag
PH 6.6
15 Gal pots

I don't understand why the pink stems. But it's happened since adding the Tall Boy. The tap water is very bad.

Any help is appreciated. Thank you

Bump

Anyone?

Hey MA MED
I have had that happen but only due to cool temps at night in my room and only under my veg light never had that happen in my flower chamber. I will say I don't use Fox Farms anymore due to problems with it, every time i had used it Beastie Bloom or Cha Ching and Big Bloom, I could never get it right no matter how careful i was with Fox Farms. So IMO only, it could be temps or could be because of those nuets. You could try flushing them out. Look like the same set up I have 5 gallon pots, Pro mIx Hp 3 600 watt Hps.
Your Using 15 gallon pots? Nice.
Well Good Luck, I sure hope you get it figured out. Keep Up Post on your progress. They look Nice to me except the red stems but i've had that happen and still got some great bud.....

Its fine

Thank you guys!

Bear420 I thought temps too but checked my 2 mini splits. When lights off one of my AC units shuts off the other I drop to 70. I'm still getting a good yield per plant but the colored stems have me off a bit. Also getting yellowing but that could be something else