3000k Or 3500k Cobs For Flower?

[Perception]

I’m adding some extra lighting (COB LEDs) to fill the corners of my tent, and increase amount of light. Trying to figure out correct spectrums.

Currently have:
-LEC315 (4200k veg bulb, 3100k flower bulb)
-4x4 tent

Adding:
-4 drop light COB LEDs for corners.
- Either 3000k or 3500k

Ideally, I was thinking I’d turn the COBs on a few weeks after popping seeds, and possibly slowly turn up brightness until I got to the flower flip, then full power I switch my primary LEC BULB to its flower bulb at this time). If I was only using the COBs for flower, I’d just buy the 3000k. But why not get some extra light in veg too? Which is why I’m considering the 3500k COBs.

I’ve heard that the more far red spectrum of the 3000k (600-660nm) can cause stretching in veg.

I was curious if you all think that the extra red of 3000k is THAT important in flower? Or if I should just get the 3500k COBs, leave them on almost the whole time, and just worry about the color spectrum coming out of my primary LEC light?

 

[JWM2]

I’d go with 3500k. I like a more white/blue spectrum and have had good results with it.

Back in the day when most were running HPS I was running a conversion bulb at around 4000k with great results vs the 2700k hps I had been running for years. But that’s me.

In fact I’d have no problems running upto 5000k and will be here shortly. It’s to supplement my vispar burples. If I was running just cobs and no burples I’d run as close to 4000k as I could. 3500k is the closest I’ve seen.

 

[Perception]

I’d go with 3500k. I like a more white/blue spectrum and have had good results with it.

Back in the day when most were running HPS I was running a conversion bulb at around 4000k with great results vs the 2700k hps I had been running for years. But that’s me.

In fact I’d have no problems running upto 5000k and will be here shortly. It’s to supplement my vispar burples. If I was running just cobs and no burples I’d run as close to 4000k as I could. 3500k is the closest I’ve seen.

Awesome, thanks for the feedback. I was leaning towards the 3500's. Figure I'd like to turn them on as early in the plants' life as possible, so why not run them through veg if I can.

 

[JWM2]

They love the bluer spectrum. That I can say for sure. You won’t go wrong either way. Still leaps and bounds better than the old hps spectrum we used for ages.

 

[Toaster79]

If it's flower only I'd go 3000K or even 2700K. If you plan to veg some under those go 90cri 3500K

 

[Burned Haze]

* Flowering only = 3000k, I’m even testing 1750k (1/9 bulbs ) right in middle. Red!

* All in one, 3500k or with 50% if bulbs 3500k and 3000k
* Veg only = 4000k

 

[DismalDude]

For flower tent I use 3000k with great results so far.

 

[Perception]

Thanks for all the notes everyone. Very helpful. I think I’ve got a good idea on how the plants will respond to Kelvin temp of these supplemental COBs, although I have one last question ya:

Do you think it would be more important to have supplemental light INTENSITY (not referencing color here) all the way through veg AND flower? Or do plants really just like that extra oomph in flower alone?

(My guess is the former, but curious on your opinions). Thanks!

 

[Perception]

Doing a little research here. Timber Grow Lights (where I plan to buy my cobs), recommends the following light intensity for Veg & flower:

-> VEG: ~500 µmol/m²s
-> FLOWER ~ 900-1000 µmol/m²s (after reducing to 12 hours a day)

So if the vegetative light intensity requirements are not as high, then maybe I should just opt for the 3000k flowering COB's, and just start turning them on right around the flip. Although I haven't found out what my LEC315 puts out yet in moles.

 

[DismalDude]

Doing a little research here. Timber Grow Lights (where I plan to buy my cobs), recommends the following light intensity for Veg & flower:

-> VEG: ~500 µmol/m²s
-> FLOWER ~ 900-1000 µmol/m²s (after reducing to 12 hours a day)

So if the vegetative light intensity requirements are not as high, then maybe I should just opt for the 3000k flowering COB's, and just start turning them on right around the flip. Although I haven't found out what my LEC315 puts out yet in moles.

I got my lights from Timber after talking with @sixstring and Dan from Timber.
Dan was really great at helping me decide which way to go after telling him what I wanted to do.Such a great company,you can't go wrong.
I got 2 Redwood VS COB fixtures at 3000k and I've never been happier.Stepped up my game so freaking much.
Very happy with my lights and kelvin choice. ;)

 

[DismalDude]

I got my lights from Timber after talking with @sixstring and Dan from Timber.
Dan was really great at helping me decide which way to go after telling him what I wanted to do.Such a great company,you can't go wrong.
I got 2 Redwood VS COB fixtures at 3000k and I've never been happier.Stepped up my game so freaking much.
Very happy with my lights and kelvin choice. ;)

Kudos to @sixstring too! Pointed me right to the pro's. ;)

 

[Perception]

I got my lights from Timber after talking with @sixstring and Dan from Timber.
Dan was really great at helping me decide which way to go after telling him what I wanted to do.Such a great company,you can't go wrong.
I got 2 Redwood VS COB fixtures at 3000k and I've never been happier.Stepped up my game so freaking much.
Very happy with my lights and kelvin choice. ;)

I spoke with Dan at Timber as well. Very helpful!

At this point, I think I'm just gonna pick up the 3500k so that I can supplement in veg (even at a lower power with the COBs, since they are dimmable) to make sure that I get more even light coverage in corners.

From all the (sometimes confusing) research I've been doing, it looks like adding the 4x COBS (200w) to my LEC315 will be a great combo to hit that 900-1000 µmol/m²s on a 12/12 cycle.

 

[DismalDude]

I spoke with Dan at Timber as well. Very helpful!

At this point, I think I'm just gonna pick up the 3500k so that I can supplement in veg (even at a lower power with the COBs, since they are dimmable) to make sure that I get more even light coverage in corners.

From all the (sometimes confusing) research I've been doing, it looks like adding the 4x COBS (200w) to my LEC315 will be a great combo to hit that 900-1000 µmol/m²s on a 12/12 cycle.

I hear ya man,I have a 4x8 for flower only that's why I went with the 3000k. ;)

 

[Perception]

Thanks everyone for the feedback.

This is what I ordered:

 

[FutureGrower]

If it's flower only I'd go 3000K or even 2700K. If you plan to veg some under those go 90cri 3500K

I dont like the 90 cri since you get alot less light out of it, they start losing efficiency. Cri is essentially a color rating index and the manufacturers throw additional coating of phosphor to achieve the true color. I know Cree at one point was using 4k? 5k? Diodes for efficiency and coating them with phosphor to get the color that's desired

 

[DismalDude]

Thanks everyone for the feedback.

This is what I ordered:

Nice,I'm using the Vero cobs.

 

[WhtChocolate]

Kudos to @sixstring too! Pointed me right to the pro's. ;)

I second that DDude. Thanks @sixstring for mentioning calling Timber. I called for QB’s talked to Dan about my 2X4X7 and he said QB’s would be fine but the long term testing results and feedback from farmers overwhelmingly said COB’s. I do think this could be since research on QB’s just isn’t there yet but either way can’t go wrong.
Again, San was awesome and I couldn’t be happier with my COB purchase. They are knowledgeable and very friendly.
Highly recommend.

 

[JWM2]

I know i'm in the minority but my own testing has shown me personally that more blue / white spectrum helps keep them from stretching, creates firmer denser buds and imo increases resin production.

We did some testing years ago between a couple dozen or so of us on Cannabis World and all had similar results. It was quite eye opening as the general consensus was the red / orange spectrum helped them more in flowering. Our tests showed otherwise. We didn't take any real measurements, its was very crudely orchestrated but conclusive enough for us to make the switch from HPS to MH conversion bulbs that were in the 4-5k color temp range.

I say this because I know some are questioning why I'd give such a recommendation. I've seen it with my own eyes, in my own garden with strains I've known very well. But that's my experience anyhow.

Kudos on your new purchase. I know you'll do great with them :-)

 

[Perception]

I second that DDude. Thanks @sixstring for mentioning calling Timber. I called for QB’s talked to Dan about my 2X4X7 and he said QB’s would be fine but the long term testing results and feedback from farmers overwhelmingly said COB’s. I do think this could be since research on QB’s just isn’t there yet but either way can’t go wrong.
Again, San was awesome and I couldn’t be happier with my COB purchase. They are knowledgeable and very friendly.
Highly recommend.

So far my experience with Timber has been great. Dan chatted me for about 20 min over their online instant message box (on website), and answered all my questions in great detail. Good customer service FTW.

I know i'm in the minority but my own testing has shown me personally that more blue / white spectrum helps keep them from stretching, creates firmer denser buds and imo increases resin production.
:)

This sounds good to me! One of my problems has been keeping the plants (from seed) short in veg, so that they don't overgrow my tent in flower. I've found that waiting for pre-flowers (roughly 50-60 days from seed pop) before flipping to flower helps my resin production, but sometimes the plants are getting BIG by then. Hoping some extra light will help keep them down. Also, all the other benefits of more light :D

 

[DismalDude]

I know i'm in the minority but my own testing has shown me personally that more blue / white spectrum helps keep them from stretching, creates firmer denser buds and imo increases resin production.

We did some testing years ago between a couple dozen or so of us on Cannabis World and all had similar results. It was quite eye opening as the general consensus was the red / orange spectrum helped them more in flowering. Our tests showed otherwise. We didn't take any real measurements, its was very crudely orchestrated but conclusive enough for us to make the switch from HPS to MH conversion bulbs that were in the 4-5k color temp range.

I say this because I know some are questioning why I'd give such a recommendation. I've seen it with my own eyes, in my own garden with strains I've known very well. But that's my experience anyhow.

Kudos on your new purchase. I know you'll do great with them :)

Saving for some quantum boards. ;)