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Red/Purple stems caused by CFL lights

B

Bill Orange

New member
Hi, so I've finally got to the point where I have 6 clones and a mother plant. I am using the same soil and nutes for all.
When I put the clones under CFL 23W or 26W, blue or red, the stems turn red/purple
When I put the clones under 20W cool white long tube, 30" or whatver it is, there are no red/purple stems. New growth will even turn back to green stems. And if I move it back to the CFLs, then the stems turn red/purple again.
I have long wondered why they turned red-purple and I suspected it was the light, but with different strains and soil, I was never certain. I have seen various posts that the red-purple stems are caused by Phosphorous deficiency, High water pH greater than 7, and heat. Even in low heat, they turn red-purple, and the other 2 are rules out because I can move them in and out of the CFL box and the red-purple stem growth stops and they turn back to nice green.

Under these 2 LED bulbs I have the stems seems to grow green and not red-purple, but I just switched them to that to test the LEDs, but the little growth I've had in a day seems not to be red-purple. That red-purple growth does not seem to be healthy as the stem gets sort of brittle and the leaves aren't as healthy looking.

So, what it it about the CFLs that could be causing this?
 
OakyJoe

OakyJoe

TC Nursery est 2020
Veteran
So you would say Colored Stems caused by CFL lights?

Seen same things here also under CFL... Interesting Topic!
 
S

sourpuss

Yeah interesting for sure... leds r dupposed to use less nutes compared to other lights. Im supposing the leds r using the nutes better and more proper. The cfls r using the nutes uneven and then cause def.... total assumptions....
 
J

jaded1

The red/purple stems are usually from it being too cold,not too hot and the plant not being able to get enough p from the soil.
Try raising the temps especially at the level of the pots and see if it goes away.
 
B

Bill Orange

New member
My temps are almost always between 70 and 80, and usually at 76.

Here's a couple of pics:

http://i.imgur.com/0LplHTo.jpg

oGgpxAT.jpg


cokbxZz.jpg


See, the growth on this last one is fine in the node, because I had moved it back to the tube fluoro:

zH64jnO.jpg
 
B

Bill Orange

New member
Yeah, I'm wondering if it's the brand of CFL, its coating on the tubing, or something about the design of certain CFLs.

About 6 months ago, it was just really bad. Not just purple/red stems, but it seemed like the CFLs were killing my plants days after putting them in the CFL box. I'd take them out and put them under the tube Fluoro and they were fine and growth would return to normal. It wasn't the temp in the box either. I checked. I have 2 fans and 2 thermometers (hi/lo positions) and a humidity gauge in there to keep the temp right around 75 all the time. Actually, it didn't seem like it, these CFLs were killing my plants. It's strange because I've grown to harvest with mostly the same CFLs over the past 2 years. But the growth and harvest I had with just tube fluoros was even better. A lot better. I'm going to switch to HPS for flowering soon, but I want to still use CFLs for veg but they've not been working so well lately.

Maybe I do need to test my pH again. No, that's not it, because if I move the plants back to the tube fluoro, they will def grow green stems and healthy plants with no problems.
 
B

Bill Orange

New member
The only other thing it could be, possibly, is the car window screen that I've line the inside of the box with. The silver puffy stuff. I'm wondering if it possibly concentrates too much light on the underside of the leaves or something.

The CFLs also seem to turn them dark purple/red regardless of the distance from the light. I've tried an inch, 3 inches, 6 inches and nothing stops the purple/red growth there.

I dunno, I got just 2 LED bulbs in there now. If the growth turns back to all green, like I expect it will, I'd say the CFLs are definitely causing it.
 
M

mr bub

Member
Ugly is in the eye of the beholder. Personally, I love those dark purple stems on young plants, especially if they bleed blood red sap when you cut a clone.
 
Snook

Snook

Still Learning
Bill Orange said:
The only other thing it could be, possibly, is the car window screen that I've line the inside of the box with. The silver puffy stuff. I'm wondering if it possibly concentrates too much light on the underside of the leaves or something.

I dunno, I got just 2 LED bulbs in there now. If the growth turns back to all green, like I expect it will, I'd say the CFLs are definitely causing it.
Click to expand...

what is that "silver puffy stuff" made out of? there are those plastics that give off gas, off gassing.. if it smells 'plastic' that smell could be affecting you stems.
 
A

acridlab

Yo,, try giving those babies a low dose of bloom nutes,, and from the look of the leaf,, it looks like u may have other things going on too.. some of ur leads have what looks like mite damage,, all those lil white specks,, check into that.. and also check and make sure ur not getting a touch of pythium.if so,, actinovate and some mykos will correct that. some of the shots kinda look like it to me.. Not saying I am right,, but it's a plan of action I would consider checking.,, peace, n hope u get it figured out
 
S

seventhchild

Member
acridlab is probably correct about the mites , that should be your biggest worry right now.if your eat up with mites it might be best to start over after a thorough cleaning.
about your purple stems,for future reference...
IMHO it seems as if your not adjusting the nutes when you change lighting.whenever you give indoor plants more or less lighting you must also adjust the amount of water,air,food,etc....you don't describe your room but it sounds like you have multiply CFL's inside a reflective tent=high light.you also have a single tube flor that probably hangs over your cloning area=low light.moving your plants from a low light environment to one of high increases the plants metabolism so you must increase the ppm of the nutes and/or the frequency of application of the h2o/nute solution.what are you growing in(the medium)?what and how much are you feeding your plants?
 
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