Best color temp for veg?

4000 or 5000?

I noticed on the datasheets that efficiency doesn't jump much between 4000-5000 or anything higher, so pointless to choose 5000 based on efficiency.

I went with 5000K bc I figured it would help keep them from stretching due to low total W/ft*ft.

Would be interesting if there was a documented side by side veg only grow, 3000, 4000, and 5000K.

Indeed it would be. I'd also like to see the cxb high cri models. for their extra red.

I tend to lean towards warmer or a mix [ my favorite was 3k/5k]....even 3K is making me 2nd guess

mc130p said:

I went with 5000K bc I figured it would help keep them from stretching due to low total W/ft*ft.

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I don't really follow that logic. Low light density is what causes stretch.

Just start a seedling and then cover it loosely with a fold of black cloth. Let there be a light opening on the end, like a pup tent.

Where will that seeding, stretch its little ass off, to get to?

OK, now take a seedling and put a 60w CFL right on top of it. It begins to leaf out in the first inch, no stretch.

I recently posted a peer reviewed, controlled Botany experiment, from a major US Agriculture University that clearly shows, the cooler the light, the less the growth, PERIOD. It is just another horrid ganja myth to me that comes straight from the sellers of CFL. It was bunk in the beginning to have two lights of different colors, alas.

I will use the same Cree CXBs Veg as I use for grow. 3000K.

I thought I saw some posts around here that were talking about people using the 2700k for flowering with the result being plants that stretched more then desired because there was a lack of blue light. That being said I used Vero 29s 4000k for veg and flower with great results on both stages. It seemed to me that 4000k was the sweet spot between lum/watt and color balance.

Created by the CFL gods? Then why did i/they (HID) users use MH and HPS instead of just HPS? I could not imagine vegging under an HPS.... I think it is apparent at least in the extreme case of 2700 vs 4000k node spacing is affected.

4000k is a superb performer.

I've been curious about the 5600k vero and the 5700k/6500k cxb series.

Keep in mind most people veg under metal halide, which are typically ~4000k. So could be something there... or not

Light density causes stretch but so does excess red in the spectrum...thats why all your cheap blurple lights come with a veg/bloom switch. Thus, the logic is that the 5000K spectrum can combat the stretch despite weak lighting. Is it sound logic? Idk, but that's the logic I used.

No. And unless you can up with some Botany on that, I don't think you are correct.

You have been marketed to. I am chasing down the science and posting it here.

The science says that is not correct.

Doer said:

No. And unless you can up with some Botany on that, I don't think you are correct.

You have been marketed to. I am chasing down the science and posting it here.

The science says that is not correct.

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Dont get angry, now. Chill out a little. And I have not been marketed to...four cobs and an IG200, I have too much light for my space, and I took 5000K and used it in the veg tent. Don't sit and think that I purchased this COB solely for it's vegtastic purposes. It is simply what I had.

I didn't bring up growth rates for a specific reason. I want my veg to go slow because I don't have a lot of extra space. Maybe that's why slower growth is not a concern for me. Node spacing is shorter under 5000K vs 3000K, that is something you will see if you ever finish your light.

Imagine how long it would take some of these designers to figure this stuff out if laymen weren't pointing everything out

Just sayin'

Time to go do house chores and keep the lady happy. Most important for life happiness...

clw makes a "vegmaster" a Flower master and a fullcycle. You might check their spec sheets to see what they went with

"Proprietary Optigrow Blend"

mc130p said:

Dont get angry, now. Chill out a little. And I have not been marketed to...four cobs and an IG200, I have too much light for my space, and I took 5000K and used it in the veg tent. Don't sit and think that I purchased this COB solely for it's vegtastic purposes. It is simply what I had.

I didn't bring up growth rates for a specific reason. I want my veg to go slow because I don't have a lot of extra space. Maybe that's why slower growth is not a concern for me. Node spacing is shorter under 5000K vs 3000K, that is something you will see if you ever finish your light.

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What are doing but passive aggressive? You did not bring it up for a specific reason. That's true. So how can I be angry with you? I thought we were discussing Botany. And you missed the point. If you believe what you put out here, today, you have been marketed to. Not an argument from me. It is true. It is baked into the early marketing of limited narrow band LED hoopla.

You can look back and this month I posted pictures and data about a very simple experiment. Take a example plant and spout it under 3 colors of lights all else the same. Warm is VEG, better. Warm is BLOOM, better.

But now you say, you chose less photon density to limit growth. That is entirely different from the question of stretch. And I would think about that question differently.

I will challenge all that is not clear Botany science. And if you show that I will accept it.

You read in anger from your own mind. I am sincere and plain spoken, the rest come from you.

Oh, and love your cheap shot, at the end there. Very endearing and not at all passive aggressive....NOT.

Positivity said:

Imagine how long it would take some of these designers to figure this stuff out if laymen weren't pointing everything out

Just sayin'

Time to go do house chores and keep the lady happy. Most important for life happiness...

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BRAVO!!

bicit said:

Keep in mind most people veg under metal halide, which are typically ~4000k. So could be something there... or not

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The latest seem to say, that photosynthesis occurs across the spectrum with the peaks of production for the Chlorophyll pair. But, it is quite possible the total of the rest of the reaction is equal to the peaks for Chlorophyll.

But, other structures carry on other work at other spectrum. So, not 2700 but 3700 would be the sweet spot, I'd say.

SDS knows a lot more about this than I.

Nice to be able to mix in the warmer colors, also I imagine.

Rahz said:

Would be interesting if there was a documented side by side veg only grow, 3000, 4000, and 5000K.

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I posted it! But, I post a lot and I can't remember the thread.

There were 3 leaves I remember from a legume. All the same age. And they were, you guessed it, small, medium and large. (there was reams of data and science, also)

The warm is a boon for Veg. The 3000K produced the largest plants the fastest.