Best color temp for veg?

[Doer]

Implicit slander is only in your mind, poor guy.

 

[Doer]

Except maybe a light that could lean towards veg or bloom with a switch..

But than color mixing becomes a issue..tradeoffs..

I was thinking mix up in several colors of white COBs but, then I think, why bother? Need science, not guess.

 

[AquariusPanta]

Moving forward is sufficient and maybe a high five?

Nope. I demand some tongue too, baby!



Ok, I'm done having fun...

 

[AquariusPanta]

You really need to be careful on the total blue %. In most cases, 5000k is as high as you need to go. 6500k is just ridiculous. I don't recommend it at all.

Remember, K values are for human vision, not plants. 6500k for CFLs is not the same as 6500k for LEDs.

4000-5000k is all you need for veg with white LEDs.

Also, mixing whites is useless. If you take 1x 6000k LED and 1x 3000k LED, you get 4500k.

6000 + 3000k divided by 2 = 4500k.

It doesn't create a special blend, it's easier just to use the 4500k, or whatever is the middle value of whatever you would otherwise mix. You get the same thing.

I wouldn't be so quick to claim such things, EH. Sure, it may be unlikely that one would get different results between using just 4500K or 6000K & 3000K but not every COB is EXACTLY as sold; one may buy a 4000K, and it may truly be 3890K when powered.

 

[alesh]

I wouldn't be so quick to claim such things, EH. Sure, it may be unlikely that one would get different results between using just 4500K or 6000K & 3000K but not every COB is EXACTLY as sold; one may buy a 4000K, and it may truly be 3890K when powered.

I was wondering how true that claim was. This is 2x 4000K vs 3000K and 5000K (CXB3070) in absolute numbers @Test current. Close but not the same.

I also did CCT calculation (not sure about it's accuracy) and while straight 4000K gives me 4305K, 3000K+5000K gives 3776K.

 

[Greengenes707]

I was wondering how true that claim was. This is 2x 4000K vs 3000K and 5000K (CXB3070) in absolute numbers @Test current. Close but not the same.
View attachment 3403029
I also did CCT calculation (not sure about it's accuracy) and while straight 4000K gives me 4305K, 3000K+5000K gives 3776K.

Interesting. It does support the theory of using differnt spectrums is not worth it vs using the middle ground temp. Borderline with the margin of error for 4k. I imagine that real life testing would be closer to the claimed K temp.
My drone came out at an average of 3050k for 6 3k cxa's. I'm still trying to get my 4ks under a spectroradiometer. It really bugs me that cree puts the 70cri 4k graph and not the 80cri. Specially when only 80 is being sold that I have found. And for us...80 should be better. And from my experience...is than 3k.

 

[JimmyIndica]

What's the temp A51 use for the white?RW?

 

[Doer]

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.

Well, imagination is not factual. And marketing is not Botany.

Many have and will Veg just fine under HPS/

 

[Doer]

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.

MH is a marketing hype. And I don't call them gods. Why do you?

 

[Scotch089]

Marketing hype sure maybe. But then why is it perceived that swapping back to mh at the end of flower ups trich production compared to hps (benefit of heavier blue) and this seems to hold true harnessing blues in leds whether it be monos cooler temp or just the nice fuller spectrum of leds in general. Greengenes side by side brings legitimate results to this concept. Same stands for cmh, are those marketing hype or a tech fit to replace the standard hps for certain needs if not all of them (different color temps)

I can see someone vegging under hps but I'd like to see the difference in end results given the difference in node spacing before flower. Side by side. I guess if you're trying to fill a space FASTER to maximize the space and TIME if you are in the business aspect and need a certain amount of turnovers every so often. But you can just as well maximize the space with tighter growth using mh if time is not a problem. And honestly it may be worth the extra time in production at the end of it all. Idk. Never done the side by side myself.

 

[bicit]

MH is a marketing hype. And I don't call them gods. Why do you?

Eh, not so much. Veggin under MH is much nicer than vegging under HPS. I've never done a controlled side by side, but plants tend to stretch more under HPS. Though it may be nicer for cloning having a touch longer node distance.

 

[Doer]

Well I mean all of it is Hype upon hype

That 6500K is the best for growth... no.

And neither is 2700k

3750k is the sweet spot to me

HPS and MH. were the only choices for photon density

And they marketed both with mythology.

 

[churchhaze]

Well I mean all of it is Hype upon hype

That 6500K is is the best for growth

And neither is 2700k

3750k is the sweet spot to me

HPS and MH. we're the only choices for photon density

And they marketed both with mythology.

I think of the whole blue for foliage, red for flowering paradigm as analogous to the "N for veg, P for flowering" bullshit you constantly hear people talking about with so much conviction and authority... of course the difference in requirement for N and P barely changes throughout the plants lifecycle. The same goes for the amount of red and blue. Slightly different SPD for veg and flowering makes a difference in morphology, but there's a reason I posted the blue and red panels on page one... I've seen so many people trying to veg with those blue things back in the mid 2000s... "You don't need any red if you're not flowering!"

Also, many people confuse "warm" with red, but it could also be yellow, orange, red, or far red... and when they think cool, they think blue, when cool can be blue, teal, or green... warmer doesn't always mean more red, and cooler doesn't always mean more blue..... etc etc..

Then, there's people who think all 4000k lamps will have a greenish tinge, even though there are many SPD that can amount to 4000k. They conclude that no 4000k lamp can be good, because 4000k is the "spectrum plants can't use". That's not even what color temperature is!!

 

[Doer]

I think of the whole blue for foliage, red for flowering paradigm as analogous to the "N for veg, P for flowering" bullshit you constantly here people talking about with so much conviction and authority... of course the difference in requirement for N and P barely changes throughout the plants lifecycle. The same goes for the amount of red and blue. Slightly different SPD for veg and flowering makes a difference in morphology, but there's a reason I posted the blue and red panels on page one... I've seen so many people trying to veg with those blue things back in the mid 2000s... "You don't need any red if you're not flowering!"

Also, many people confuse "warm" with red, but it could also be yellow, orange, red, or far red... and when they think cool, they think blue, when cool can be blue, teal, or green... warmer doesn't always mean more red, and cooler doesn't always mean more blue..... etc etc..

Then, there's people who think all 4000k lamps will have a greenish tinge, even though there are many SPD that can amount to 4000k. They conclude that no 4000k lamp can be good, because 4000k is the "spectrum plants can't use". That's not even what color temperature is!!

Exactly. Pin this post.

 

[JimmyIndica]

If I was in the market for full cycle fixture ? Vero 4000k,cxb3070 4k!

 

[bicit]

I've been quite happy with my 4000k emitters.

The 2700k 97 cri ones, not so much....

 

[Rahz]

I've been quite happy with my 4000k emitters.

The 2700k 97 cri ones, not so much....

What kind of wattage are you running those two lamps at? I assume you've used both individually? Will you describe the differences you've noticed?

 

[Rahz]

Something interesting I've noticed with the new Veros, since the efficiency on the warmer temps is up there's very little visual output difference between 3000, 3500 and 4000. Maybe 200 lumens difference between them @ 1.05 or 2.1A.

 

[bicit]

What kind of wattage are you running those two lamps at? I assume you've used both individually? Will you describe the differences you've noticed?

~42 watts. Unfortunately no, I didn't run them separately. I've only run the 4000k on it's own. I may have to give it a run. I have run them 2:1(in both combinations) over tomatoes and herbs. Stretching actually wasn't much of an issue, however it caused plants like basil and spinach to bolt. I removed the 2700k emitters and bolting doesn't seem to be an issue anymore.

They've been collecting dust since then. I only bought them cause I though I needed 'moar red' . They're pretty inefficient.

4000k emitters gives me very similar results to metal halide.

 

[Rahz]

I'm beginning to believe the "more red" that's needed isn't something we can get in white LEDs... at least not in the amounts needed for the Emerson effect to function.

All the runs I've done at 3350K (2:1 mix of 3000/4000) stretch stops very early in flower.

I've completed one run at 3000K, had massive stretch... however I only got the lamp done after vegging under T5 tubes and going about 2 weeks into flower. I hypothesize that the switch in light had something to do with it. I'm on my second run with 3000K and just going into week 5 it looks like the stretch is similar to the results I've had with 3350K, minimal.

I'd be curious to know if anyone has vegged with both 3000 and 4000. In the case of both my lamps operating at sub 4000K temps the veg has been "bushy" with plants typically showing as much lateral growth as vertical, very thick and leafy. I'm not sold on the +4000K veg yet. I do like the idea of higher efficacy with the higher color temps, but there doesn't seem to be a meaningful variation between the various temps in that regard, at least with Vero.

I just checked and it's the same with CXBs, though there is a 70 CRI option that opens up with the 4000K temp that does have higher efficacy.