So close! What happened? Can an LED turn a stem pink/purple

Originally Posted by Mr. X

Hey all,
This is my second grow. First dried up while I was on vacation. I've got two problems. I was really disappointed yesterday to come home to temperatures of 93 degrees! I'm on week 7 of flowering and have never had any real heat issues. Actually last month I looked into a heater because my temperature was in the mid-60's! I recently purchased a 90w UFO LED grow light and up until now I had no problems with it. My lighting was as follows:

1 x 90w UFO
2 x 42w CFL's

Up until now for the most part I have been in the mid-70's. I tried turning up the fan in the box to no avail. Next I added a huge fan outside the box in desperate attempt to lower temps. Somehow this increased temperatures even more, so I took it out altogether. Outside the temperature is 75 so I do not understand the heat increase. Do I need to vent the LED better? For now i took out the UFO and replaced it with:

3 x 42w CFL's
1 x 23w CFL

So far the temperature is around 82. Is that ok?

The other problem is stem color:
Upon inspecting my plant i noticed that the stems on some of the fan leaves are a purple pink color . I have been feeding Fox Farms Big Bloom to my plant every two weeks. So I don't think it is a potassium deficiency. Correct me if I am wrong. I started noticing the stem color today and it has been a week since I added my LED. I am not sure how long the stems have been like this but is it a problem? It seems like only the stems that the LED's light could reach turned that color.

How does my plant look? What can I improve on?

BTW I searched for "LED grow light red stem color" and I found nothing.

Any help is greatly appreciated!

Red stems mean nothing most of the time. They can be a sign of P deficiency, but since loads of weed strains have red stems even when healthy you are better off ignoring it. Although your leaves do appear to have a purple tinge, which is also a sign of potential P deficiency. I'd say heat is your main concern though...that and lack of space...

It sounds to me that you aren't extracting heat out of your grow area. The heat went up because you put a 90W heater in there (LEDs give off 70% of the electrical power put into them as heat, so actually more like a 63W heater, but that's still plenty to get the temp of a small grow space up if it isn't well ventilated).

My grow area is as follows.
I have a 80"l x 48"w x 60"h shed in my yard.
Inside this is my 24l x 24w x 38h grow box.
I have a fan inside my box, passive intake and a computer fan for exhaust.

While the shed isn't air-tight, there isn't an abundance of fresh air entering it either.

I forgot to mention that this is NL from Nirvana I think it was.

Nutrients are hard to measure without a ppm meter and because when I water I don't usually use a full gallon so using the included proportions is hard to do.

I have a tent coming tomorrow so I am not too worried about space.

How would you guys recommend measuring nutes? Can I get a reliable ppm meter for around 30 bucks?
Thanks

bump. Any advice?

cut a massive hole in it and get some air moving,next ditch the cfl's they are putting out to much heat for you .that led is plenty for that one plant mount it on top and i would also start bending and training the plant sideways to get max. yield's. temps are hurting you right now .

Thanks. Cut a hole in the fridge or in the shed?
I now have:

1 x 42w CFL
1 x 90w LED

pink stems means P is clogging your plants veins, usually because it gets below 65 degrees. an easy fix is to feed with a little more K because K helps with circulation quite a bit. the singed tips of your plant means it wants more K too

Is that a bad thing? Should I figure out a way to keep it warmer at night?

I fed it with Fox Farms Big Bloom today but I am a little confused. The ratios are 0.01-0.3-0.7 compared to the 2-8-4 of non-organic Tiger Bloom. Is the Big Bloom really that weak?