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Topic starter

What causes red stems 

11 Answers

Sometimes it's just genetics sometimes your stems could be getting too much light but it could also be a phosphorus deficiency

I Like Big Buds and I Can Not Lie!


Most of the time it’s a reaction to the strong led lights. If you look at the underside of the red stem, where the light can’t directly hit, and the stem isn’t red on that side, then it’s light. It can be a phosphorus deficiency but most of the time it isn’t. 

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Yep almost guarantee it's the light, or genetics. 

I feel like a, like a slice of butter... melting on top of a big-ol' pile of flapjacks... yeah.

Topic starter

Thinking so too because they're all in the same mix of soil and it seems like only a few of the bag seeds are turning red


Am currently having this issue so thought I'd come to this thread for advice seeings it was already here


I think I've underestimated the potential of my lights. They're VS1000's and I've got them about a foot from the top and at 100%. Because they were entry level lights I thought they might have struggled so put them closer. I'll double the distance and see how it turns out. Also I've just changed a week ago to bloom nuts with higher P,K. What's really thrown me was no signs of tip burn or bleaching hinting to the lights being close but in my case it maybe genetic as the ZDP doesn't show signs of this but has it's light at the same height. With these girls just ending week 2 flower around where should my PAR be as I can use the app on my phone to adjust it.

"What's the charge officer, eating a meal? A succulent Chinese meal?"


I always use a meter to optimize placement of lights and relative to shape size and phase of plants - they are pretty cheap  - like 2-3 seeds worth of money. I try to achieve 40k - 50k lux reading at top of all stems during veg and 55-65k lux reading on all viable bud sites during flower.

Topic starter

I like to keep about 600 in veg 8 00 in flower mybe 900-1000 even if they can handle it you got him ease them into that light sometimes yeah that light was way too close bro. These LEDs are stronger than you think. 

Raising it up definitely is not going to hurt. Spread that spectrum a little bit. See what happens

Topic starter

As you can see I was getting red stems as well lights are strong man I'm raise them up a little bit it seemed to help


This is where I'm currently at with the app I'm using

IMG 20230404 225141

 That's the levels at the top of the canopy with the lights lifted up a foot higher 


"What's the charge officer, eating a meal? A succulent Chinese meal?"


I know I've cause it before with lights, just turned up too far or too close to them, maybe either go up a bit in distance or back the dimmer down and slowly increase to see what she likes

BiggersBuDs BiggersBuDs Topic starter April 4, 2023 3:40 pm

@drgreenthumbs88 honestly if you have room to raise them just raise the lights cuz you going to get a wider coverage area

BiggersBuDs BiggersBuDs Topic starter April 4, 2023 3:41 pm

@drgreenthumbs88 I have made this mistake before with them too close when I raise the lights up they always seem to love it more

BiggersBuDs BiggersBuDs Topic starter April 4, 2023 3:42 pm

@drgreenthumbs88 than dimming it


Yes when possible raising them is the answer for sure.. 

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