Color Temperature

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Tkb88
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Does anyone have any experience with the different color temperatures of LED's and plant growth? I'm going to be starting some seedlings soon and was wondering of how much of a difference it will make? Specifically I'm looking at making some lights with the Bridgelux EB series. I've made a couple lights for supplemental growth so far with mostly 3000k lights and haven't noticed any abnormal growth. Looking at the spectrum graphs I'm wondering if the 4000k might have a better distribution?

http://www.bridgelux.com/sites/default/ ... %20A_0.pdf

Thanks!
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LEDG
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Here’s what I’ve got going on right now. 4000K on the left, 3000K 80 CRI in the middle, 3000K 90 CRI in the right. Some of the plants look a little funky because I’m still fighting with aphids. They have been managed up until recently when I had to leave home for a few days so I’m having to hit the leaves pretty hard with my soap solution.

4000K is short and stocky. 3000K 80 is bigger but less dense. There are more flowers on the 3000K right now. 3000K 90 is in between and looks great.

4000K vs 3000K 80:
4A730F9D-82BD-4530-B057-79ED7FEE37C6.jpeg
4A730F9D-82BD-4530-B057-79ED7FEE37C6.jpeg (3 MiB) Viewed 1384 times
4000K:
C23054D7-8750-42C9-865F-8D09025DA1DF.jpeg
C23054D7-8750-42C9-865F-8D09025DA1DF.jpeg (2.88 MiB) Viewed 1384 times
3000K 80:
3B2586A7-DEBA-472B-8E1E-21FB9E4592AA.jpeg
3B2586A7-DEBA-472B-8E1E-21FB9E4592AA.jpeg (3.16 MiB) Viewed 1384 times
3000K 90:
C8CE861B-AB03-423D-B3DE-306B6A10C3CE.jpeg
C8CE861B-AB03-423D-B3DE-306B6A10C3CE.jpeg (3.12 MiB) Viewed 1384 times
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Tkb88
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Great comparison!

Were those started from seeds?
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LEDG
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Yes. Same pack.
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Tkb88
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Great thanks! From some of the things I've read it sounded like it would really affect the growth of the seeds. Most of those were based on CFL lights though. It's hard to know the color spectrum on some of them I think.

If found this interesting article if anyone is interested:

http://hortsci.ashspublications.org/con ... /1478.full
Buck5050
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90 cri FTW!
LEDG,
If you get a chance can you measure stem thickness? Unless its negligible. If we can get you running coco from a single res we could turn your basement into a growlab and eliminate some minor variables. The work you do now is by far better than most and I appreciate everything you do for the indoor grow community. Keep on doing your thing and Thanks again!
Tkb88
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Do you know if there are any strips that have a 90 CRI? I wonder how a 3500K would be at 80 CRI?
sweeper
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Tkb88 wrote:
Tue Jan 09, 2018 7:25 pm
Do you know if there are any strips that have a 90 CRI? I wonder how a 3500K would be at 80 CRI?
These aren't 90 cri, but they are 3500k. I am curious if they will work well/at all. I've not quite got together what all to look for on strip/midpower leds.

https://www.digikey.com/product-detail/ ... ND/6624002
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LEDG
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I have not yet seen a 90 CRI strip. I’m sure we’ll see one soon enough.
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