The far red thread

jokefox

Active Member
Whats the watts per square foot that you want the far red? And what distance from canopy? I've been trying to figure out how many I need for a 4x8 table and the distance from eachother and the canopy they need?

Or just get a strip and put them in the top corners shining down kinda diagonal. Or used as side lighting. Someone help my brain please
 

DCcan

Well-Known Member
Whats the watts per square foot that you want the far red? And what distance from canopy? I've been trying to figure out how many I need for a 4x8 table and the distance from eachother and the canopy they need?

Or just get a strip and put them in the top corners shining down kinda diagonal. Or used as side lighting. Someone help my brain please
Every light is different, depends on what spectrum and intensity you start with is one answer.
Red for end of day or red for growth would get you another answer.

Most people just pick a wattage and add 10-15% reds diffused across their light bars for simplicity.
How to control them brings up more decisions based on what you are doing with red
 

vitalsine

Well-Known Member
I'm using / trying for the first time 20w of far red (they're in a block rather than strips) around 12 -15" from the canopy.
What bulbs/lights are you using? They're just a 20w fixture/bulb? I am super interested in this, I love the idea. Would def invest in something like this.
 

numberfour

Well-Known Member
What bulbs/lights are you using? They're just a 20w fixture/bulb? I am super interested in this, I love the idea. Would def invest in something like this.
Its a fixture with 20x double 45mil Epileds chips with 120° light angle. Stoner moment :eyesmoke: 45w not 20w. These were the only 660nm and 730nm lights I could just purchase due to covid making delivery times way out of my flowering time frame.

730nm on right
DSC00516 - Copy - Copy.JPG
 

vitalsine

Well-Known Member
Its a fixture with 20x double 45mil Epileds chips with 120° light angle. Stoner moment :eyesmoke: 45w not 20w. These were the only 660nm and 730nm lights I could just purchase due to covid making delivery times way out of my flowering time frame.

730nm on right
View attachment 4667204
Sweet! Did you wire these up yourself? I'd prefer strips like yours but having a hard time finding anything similar on Amazon. I did come across some bulbs that might, I was thinking of grabbing two 660nm and two 730nm... would these work?


I figure because it is only supplemental, running for 20 mins before/after lights, they should do the trick?

**EDIT** I lied, I can't find any 730nm bulbs lol.

Just stumbled across this:

Would one of those be enough for a 5x5 for lights off?
 
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numberfour

Well-Known Member
Sweet! Did you wire these up yourself? I'd prefer strips like yours but having a hard time finding anything similar on Amazon. I did come across some bulbs that might, I was thinking of grabbing two 660nm and two 730nm... would these work?


I figure because it is only supplemental, running for 20 mins before/after lights, they should do the trick?

**EDIT** I lied, I can't find any 730nm bulbs lol.

Just stumbled across this:

Would one of those be enough for a 5x5 for lights off?
No they came plug and play, I've sent you a DM with the sellers info.

Cutter, HLG, Rapid Led and a few other companies do stand alone far reds in pucks / strips etc, defo worth checking out

Timings are up to you, this thread has has a few different ones mentioned, 20 minutes may cause excessive stretch with the far reds.

I'm probably not the best person to ask tbh, there are people with a lot more experience in this thread than me, but the forevergreen website states the light will fully cover a 4' wide grow tray. May be worth contacting them and seeing how much the light diminishes after the 4'.
 

Barristan Whitebeard

Well-Known Member
Sweet! Did you wire these up yourself? I'd prefer strips like yours but having a hard time finding anything similar on Amazon. I did come across some bulbs that might, I was thinking of grabbing two 660nm and two 730nm... would these work?


I figure because it is only supplemental, running for 20 mins before/after lights, they should do the trick?

**EDIT** I lied, I can't find any 730nm bulbs lol.

Just stumbled across this:

Would one of those be enough for a 5x5 for lights off?
"The Far Red Lightbar covers up to a 5’ x 12” area with very even intensity at 30” above canopy. It will cover a much larger area when used during lights off to manage the Emerson Effect in cannabis."

According to the FGI website, the far red light bar covers up to 5 square feet at 30" above the canopy when used in conjunction with main lighting.

The information becomes vaguer after that regarding the coverage of the light bar when used while the main lights are off. Whoever wrote the webpage is also mistaking early flower initiation for the Emerson Effect (which requires the main lights to be on with the far red light bar of course).

You could try contacting FGI and ask them if they have an actual recommendation for coverage area of the light bar when used as a flowering initiator.
 

Barristan Whitebeard

Well-Known Member
Sweet! Did you wire these up yourself? I'd prefer strips like yours but having a hard time finding anything similar on Amazon. I did come across some bulbs that might, I was thinking of grabbing two 660nm and two 730nm... would these work?


I figure because it is only supplemental, running for 20 mins before/after lights, they should do the trick?

**EDIT** I lied, I can't find any 730nm bulbs lol.
HLG sells a Flowering initiator Far Red Bulb. Peak wavelength: 730nm.


I've also seen some bulb lights in this wavelength being sold on eBay.
 

vitalsine

Well-Known Member
HLG sells a Flowering initiator Far Red Bulb. Peak wavelength: 730nm.


I've also seen some bulb lights in this wavelength being sold on eBay.
I actually scooped one of those HLG bulbs last night. Got a cpl clamp fixtures as well. Now just gonna grab a 660nm.
 

vitalsine

Well-Known Member
So I need a tldr; lol. I now have 2 35w 660nm bulbs and 2 15w 730nm bulbs. From some reading I did in this thread and elsewhere, I kick the 660nm on for 10 mins (comes on 7min before lights on) and then at lights off the 730nm kicks on (comes on 3 mins before lights off). Now to achieve the Emerson effect, do I have to run these during my normal light schedule? From what I can tell you have to run both spectrums at once to induce the effect. I know I could skim the 100 pages of this thread but hoping someone can save me the time and chime in now that I have everything in place.

**EDIT**

So here is what I have come up with...

Flower Week 1-3
7:53PM 660nm bulbs on
8:00PM LEDs on
8:03PM 660nm bulbs off
7:57AM 730nm bulbs on
8:00AM LEDs off
8:07AM 730nm bulbs off

Flower Week 4-~10
7:53PM 660nm on
8:00PM LEDs and 730nm on
8:00AM LEDs and 660nm off
8:07AM 730nm off

Anyone with some knowledge on this subject would be awesome if you could chime in! THANKS!
 
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mauricem00

Well-Known Member
So I need a tldr; lol. I now have 2 35w 660nm bulbs and 2 15w 730nm bulbs. From some reading I did in this thread and elsewhere, I kick the 660nm on for 10 mins (comes on 7min before lights on) and then at lights off the 730nm kicks on (comes on 3 mins before lights off). Now to achieve the Emerson effect, do I have to run these during my normal light schedule? From what I can tell you have to run both spectrums at once to induce the effect. I know I could skim the 100 pages of this thread but hoping someone can save me the time and chime in now that I have everything in place.

**EDIT**

So here is what I have come up with...

Flower Week 1-3
7:53PM 660nm bulbs on
8:00PM LEDs on
8:03PM 660nm bulbs off
7:57AM 730nm bulbs on
8:00AM LEDs off
8:07AM 730nm bulbs off

Flower Week 4-~10
7:53PM 660nm on
8:00PM LEDs and 730nm on
8:00AM LEDs and 660nm off
8:07AM 730nm off

Anyone with some knowledge on this subject would be awesome if you could chime in! THANKS!
your plants would benefit from running 660nm during the entire lights on period and then 730nm for 10 minutes after lights out and maybe a few minutes mid day to get the Emerson effect but keep in mind that greenhouses use deep red to prevent flowering during fall and winter. I'm a T5 grower but use LED pontoons during flowering and running 730nm for 10 minutrs after lights out lets me flower on a 13.5/10.5 light schedule
 
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plebschmo

Active Member
Hey guys :)

I've recently installed a 12 x 730nm Cree XP-E2 Far red board into my garden - now I have 2 x QB288 v1 boards and 2 x QB288 v2 boards I also installed 24 x 680nm XPG-3 photo red diodes via 2 more boards. . I've spent the last couple of days reading this thread lol.

I want to do end of day far red initiation.

Going by whats been stated in this thread I want around 3000 - 4000 umol/m2 to initiate plant sleep without causing excess stretching.

I've only got 1 plant and its canopy will probably not extend much beyond 1m2.

From the Cree XP-E2 Data sheet (https://www.cree.com/led-components/media/documents/XLampXPE2.pdf - page 15) it says that each LED emits about 2.1umol/s. So 12 x 2.1 umol/s = 25.2 umol/s emitting from the strip so to get 3000umol/m2 it would take about 120 seconds and for 4000 it would take about 160 seconds.

Are these calculations right? Should I only be running the far red for between 120 - 140 seconds after lights out? This seems to short to me with everyone saying either 5 or 15 minutes...

Perhaps @Randomblame could chime in?

Thanks for your help guys.
 

Rocket Soul

Well-Known Member
Hey guys :)

I've recently installed a 12 x 730nm Cree XP-E2 Far red board into my garden - now I have 2 x QB288 v1 boards and 2 x QB288 v2 boards I also installed 24 x 680nm XPG-3 photo red diodes via 2 more boards. . I've spent the last couple of days reading this thread lol.

I want to do end of day far red initiation.

Going by whats been stated in this thread I want around 3000 - 4000 umol/m2 to initiate plant sleep without causing excess stretching.

I've only got 1 plant and its canopy will probably not extend much beyond 1m2.

From the Cree XP-E2 Data sheet (https://www.cree.com/led-components/media/documents/XLampXPE2.pdf - page 15) it says that each LED emits about 2.1umol/s. So 12 x 2.1 umol/s = 25.2 umol/s emitting from the strip so to get 3000umol/m2 it would take about 120 seconds and for 4000 it would take about 160 seconds.

Are these calculations right? Should I only be running the far red for between 120 - 140 seconds after lights out? This seems to short to me with everyone saying either 5 or 15 minutes...

Perhaps @Randomblame could chime in?

Thanks for your help guys.
2.1 umols will be relative to a certain wattage per diode. If you allready controlled for this, then yeah, youre right. Most people run too much eod far red, usually cause people was using mechanical timers with lowest time interval being 15 min. Random is sadly a bit MIA but im.familiar with his calculations.
 
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