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Color temperature for Flowering & Veg.

Posted: Mon Jan 29, 2018 8:47 am
by Hyakutak
Hi

I'm currently preparing a build for 20x 500w Samsung F-Series based lights (LM561C led).

I will use 10 of them for flowering and 10 of them for veg. Is it a good idea to buy different color temp led?

I've read This guide from SAG and I wonder what is the best option?

half 5000K & half 3000K?

In the color temp comparison video from led gardener, the 3000k seem's to do better than the 4000k. But I've read that higher color temp is better for veg. Why that result?

Thank you in advance!

Re: Color temperature for Flowering & Veg.

Posted: Mon Jan 29, 2018 10:49 am
by Grower
macthezazou wrote: ↑
Mon Jan 29, 2018 8:47 am
Hi

I'm currently preparing a build for 20x 500w Samsung F-Series based lights (LM561C led).

I will use 10 of them for flowering and 10 of them for veg. Is it a good idea to buy different color temp led?

I've read This guide from SAG and I wonder what is the best option?

half 5000K & half 3000K?

In the color temp comparison video from led gardener, the 3000k seem's to do better than the 4000k. But I've read that higher color temp is better for veg. Why that result?

Thank you in advance!
If i am not mistaken HLG already did a test about this.
If you mix 10x 3000k strips and 10x 4000k strips the overall spectrum is a 3500k.
Anyway there should be plenty blue wavelenght in any spectrum we use, probably due to the way they are built

Re: Color temperature for Flowering & Veg.

Posted: Mon Jan 29, 2018 12:17 pm
by Hyakutak
I don’t want to mix 4000k and 3000k... I want to have half lights for flowering and the other half for veg...

Re: Color temperature for Flowering & Veg.

Posted: Mon Jan 29, 2018 3:55 pm
by Jolly Green Giant
welcome to the forum 😁

I would say either 3000k or 2700k for flower.. 4000k for veg..

I have a 4000k and 5000k veg lights over different mother's ( same strain different seed) I can notice differences between the plants under one vrs the other... my 5000k is smaller in plant/ leaves size....tighter structured ( pain to get a lot of clones from) the side branching is a little slower also... my mom under the 4000k is the complete opposite. I had to(im switching moms they are in flower atm) trim that girl back it seemed every 5-6 days so it wouldn't grow into the light... way better noding( I know the other plant could be tighter genetically but the light does seem to play a part) the Leafs look happier and are way fatter..

for flower either or... pretty much preference.. I run 3500k for the extra blue... but the 3000k should have enough blue( in that guide the talked about blue added to the 2700k) to get that guides results..

Re: Color temperature for Flowering & Veg.

Posted: Mon Jan 29, 2018 10:44 pm
by majorana
Higher temperature (5000K) should give you tighter nodes, so most would go for that. You can see the video about that fairly recently in the blog as well.

While we're on this topic, I'm wondering how much does everybody here light during veg. Usually the discussion revolves around flowering (W/sqf), but I've learned I've been over-lighting during veg in the past.

Re: Color temperature for Flowering & Veg.

Posted: Tue Jan 30, 2018 4:35 am
by LEDG
majorana wrote: ↑
Mon Jan 29, 2018 10:44 pm
Higher temperature (5000K) should give you tighter nodes, so most would go for that. You can see the video about that fairly recently in the blog as well.

While we're on this topic, I'm wondering how much does everybody here light during veg. Usually the discussion revolves around flowering (W/sqf), but I've learned I've been over-lighting during veg in the past.
I’ve been searching for that magic number too. Seems a lot of people are looking for around 250 umoles/m2/s for veg which would work out to half power or less of flowering.

Re: Color temperature for Flowering & Veg.

Posted: Tue Jan 30, 2018 8:46 pm
by Sativant
I think I've been over lighting too. My plants have been so bushy as to be very hard to train and prune. Right from the start. I don't have a light meter to see how much light I am putting down, but I'm drawing about 250 watts (2x 300W chinese leds) from the wall to cover a 2'x2' tent for veg. and flower.
When I was running a mother/clone veg box with just 4 or 5 cfls my plants had "looser" node spacing and were perfect for taking clones from. When I flowered those plants I had great results. I plan on adding a QB or strip @ 4000K for veg.
The conversation about color temperature is a an interesting one. Sorry if I veered off course...

Re: Color temperature for Flowering & Veg.

Posted: Thu Feb 01, 2018 2:32 am
by Jolly Green Giant
LEDG wrote: ↑
Tue Jan 30, 2018 4:35 am
majorana wrote: ↑
Mon Jan 29, 2018 10:44 pm
Higher temperature (5000K) should give you tighter nodes, so most would go for that. You can see the video about that fairly recently in the blog as well.

While we're on this topic, I'm wondering how much does everybody here light during veg. Usually the discussion revolves around flowering (W/sqf), but I've learned I've been over-lighting during veg in the past.
I’ve been searching for that magic number too. Seems a lot of people are looking for around 250 umoles/m2/s for veg which would work out to half power or less of flowering.
LG what's the umole/m2/s conversion to ppfd again??? umole/m2/s =ppf correct? ( I forget I haven't watched GM5 in awhile.. lol he use to throw those equations around every other stream)

I know I was shooting for 800ppfd across my 4x4 area.. then half that for vegging. which probably is over lighting them πŸ˜„

Re: Color temperature for Flowering & Veg.

Posted: Fri Feb 02, 2018 3:18 am
by LEDG
Jolly Green Giant wrote: ↑
Thu Feb 01, 2018 2:32 am
LEDG wrote: ↑
Tue Jan 30, 2018 4:35 am
majorana wrote: ↑
Mon Jan 29, 2018 10:44 pm
Higher temperature (5000K) should give you tighter nodes, so most would go for that. You can see the video about that fairly recently in the blog as well.

While we're on this topic, I'm wondering how much does everybody here light during veg. Usually the discussion revolves around flowering (W/sqf), but I've learned I've been over-lighting during veg in the past.
I’ve been searching for that magic number too. Seems a lot of people are looking for around 250 umoles/m2/s for veg which would work out to half power or less of flowering.
LG what's the umole/m2/s conversion to ppfd again??? umole/m2/s =ppf correct? ( I forget I haven't watched GM5 in awhile.. lol he use to throw those equations around every other stream)

I know I was shooting for 800ppfd across my 4x4 area.. then half that for vegging. which probably is over lighting them πŸ˜„
umoles/second = PPF
umoles/meter squared/second = PPFD

Re: Color temperature for Flowering & Veg.

Posted: Fri Feb 02, 2018 12:01 pm
by austynn2001
I've seen 3500k all the way through work very well in a bunch of different grows. That's what I'll be starting with when I get my strip build together.