The far red thread

[420masterofdon]

I believe the one i linked might be too long for your setup. That puck i thought was only a far red initiator, does it have red and deep red diodes too, you need them for emerson?

I’d go with 15 mins, won’t do anything negative if other lights are out. The story (anecdotal as best i can tell) is that you can go upto 2 hours longer lights off (10:14) to get some additional flowers, and that the get closer to 12:12, the extra sleepytime helps shorten the duration of flowering period.

I’m running both full lightson emerson and 15 min lightsoff far red (12:12), my feeling is that the emerson is doing way more than the lightsout far red, but i have no evidence to present.

I trust @Randomblame ’s opinion, maybe he’ll chime in.

One suggestion, don’t start emerson or initiator until after stretch, inkess your trying to boost internode length..

oh super interesting that you're mentioning that OK!
So don't start the far red regime until the initial stretch upon flowering

Thanks for the tips! <3

 

[Or_Gro]

oh super interesting that you're mentioning that OK!
So don't start the far red regime until the initial stretch upon flowering

Thanks for the tips! <3

Unitl after stretch has ended, around wk3 for 8 wk strain, basically when you see pistil balls form on tips, signalling transition from veg to flower is complete.

Far red during veg can lead to dramatic stretch overnight. Sometimes what you need, but most times what you want to avoid.

You’re welcome. I hope it works well for you.

 

[420masterofdon]

Unitl after stretch has ended, around wk3 for 8 wk strain, basically when you see pistil balls form on tips, signalling transition from veg to flower is complete.

Far red during veg can lead to dramatic stretch overnight. Sometimes what you need, but most times what you want to avoid.

You’re welcome. I hope it works well for you.

I would've cried upon seeing my tops stretch over the scrog .
This is my plant today on day 48 of vege. Scrog should go on these next couple of days and then shortly after that I'll flip to flower. My height is 6 foot but I for sure want to keep things as low and non stretched as possible.

 

[Or_Gro]

FWIW

Spectrums:

8 x QB288 V2 (3000k) + 4 x QB35 V2

Note: supplemental reds per single QB35: 8x630nm + 6x660nm + 4x730nm (emerson effect)

HLG QB550 v2 (3000k)

Note: this is what the first spectrum should look like without the supplemental reds.

HLG QB96

Note: supplemental reds per single QB96:
16x630nm + 16x660nm

HLG QB96 + Far Red
[Spectrum to go here]
Will be testing QB96 running 12 hrs lightson during flowering, with far red running 12hrs lights on:15 mins lightsoff, (both emerson and initiator effects)

 

[KonopCh]

One suggestion, don’t start emerson or initiator until after stretch, unless you’re trying to boost internode length.

I tought you don't get much stretch if you use Emerson (660 + 730)?

 

[Randomblame]

There are a few things I would like to mention.

@420masterofdon
These 700mA far-red puks should have ~14-15μMol/s/m²(calculated with 40% efficiency). Thats ~40μMol/s in a 0,36m² tent(2x 2'). One need ~2000-4000μMol(not per s/m², just μMol) to put the girls into sleep mode so you need to run it only for 50-100 seconds to give them the amount of far-red they need. It works with the dose princip just like UV..

If you use far-red you'll ALWAYS get more stretch! Thats normal behavior! It depends on how much they get.
I usually use 2000μMol EoD treatment at the beginning(12/12h) and increase slowly to 4000-5000μMol until finish. When the stretch is done I also use it over the day for other beneficial effects(increased leaf temps, compensation between PS-I and PS-II, emerson effect). This way the additional stretch is pretty small and the plants finish only ~2-4' taller in the end.

White light already contains red and deepred wavelength so you should profit from emerson effect even without additional red/deepred diodes. For this reason many user have switched to CRI90+ because it has much more red and deep-red and twice as much far-red compared to CRI80. Even though CRI80 is more electrically efficient the better spectrum compensates for this and depending on the strain you are using you can get even better yields in less time if you use CRI90.
But remember, the emerson effect gets weaker with increased brightness. With 1500μMol/s/m² there is no improvement anymore. With only 400-500μMol/s/m² you'll see huge improvements.
This is how mother nature has created a way how plants get along well with less light.
But when you add more red/deepred wavelength you make your whole light more efficient and depending on the brightness level it also increase the emerson effect.
I've added a few science papers about red and far-red and a link to an interview with doc hernandez. I know, its a lot to read and the interview starts with UVB light but it's still worth watching it completely.

 

[Randomblame]

I tought you don't get much stretch if you use Emerson (660 + 730)?

Depends on how much you use. The more far-red the more stretch!

 

[KonopCh]

Depends on how much you use. The more far-red the more stretch!

Yea, only FR diodes causes a lot of stretch.
But with 660 a lot less or nothing. I think we all have more 660 than 730 anyway.

So @Or_Gro missed a little.

 

[Randomblame]

You also get more stretch with 660 "and" 730nm at the same time. It only depends on the amount of far-red and the ratio you use. In full sun light the ratio is maybe 55:45% and there is no stretch but in the shade red is reduced and the ratio is more like 25:75%. This cause SAS!
But no one would use such an amount of far red indoors and with the usually used 3:1 or 2:1 ratio there is only minimal more stretch compared to CRI80. For this reason I start using it over the day when the stretch is done but I only use far-red diodes + CRI80/90. No extra deep reds..
The length of far-red EoD treatment has much more effect on stretch but thats another thing.

 

[Or_Gro]

I’m going to leave the technical side to @Randomblame and focus on the practical effects as a grower, not a light expert.

I have a grow going on currently using the lights that produced the first spectrum above, for 12:12, plus far red for 15 mins after lightsout. I started both emerson and initiator at flip, not after stretch.

The amount of stretch that has occurred is negligible. It would be the last thing anyone would notice, if at all, when they look at the plants.

We sometimes get caught up in trying to be super precise rather than just accepting accuracy. Others can spend their time identifying the precise amounts, but for me good enuff is knowing that If you have more red & deep red than far red, stretch is not a significant issue.

The benefits from emerson are plainly obvious to me, and outweigh any concerns about stretch. The benefits of the initiator remain to be seen, perhaps there is some incremental wt gain or shortening of the flower period (impossible to tell in my grow for first one, too early to tell on second one), but certainly stretch has been minimal.

Now, a single grow using my strains (sativa-dom), under my grow’s conditions, doesn’t statistically prove my beliefs to be true. But i’ll go with my gut until anyone else sets up a statistically proper cannabis experiment.

I’m sold on emerson; and willing to hope on the initiator, especially since it hasn’t done anything visibly negative and only costs me the minimal cost of the light and 15 mins of electricity.


“Nyc diesels” on left, super silver hazes on right, day 50 of ?84?

 

[Or_Gro]

@Randomblame could you please take a look at this description of hlg qb96 elite, and let me know what the minimum number of far red diodes or growmau5 pucks would be needed to get emerson effect?

“QB96 Elite V2 is a white LED Board with boosted red spectrum. Each Board is powered by 64 high power white LED, 16 630nm Red LED and 16 660nm Deep Red LED.” If they’re the same reds in the qb35, then specs can be found here: https://www.luminus.com/products/horticulture

My hlg qb35s have four 730s, six 660s, and eight 630s; so i’m thinking about 8 or so 730s per qb96.

I can’t believe they didn’t substitute a few 730s fot the other reds, but the silver lining is that with separate far reds you can run the far reds in a less complicated manner to get both emerson and initiator - run fr full lightson plus x minutes....

Thanks man!

 

[Randomblame]

@Randomblame could you please take a look at this description of hlg qb96 elite, and let me know what the minimum number of far red diodes or growmau5 pucks would be needed to get emerson effect?

“QB96 Elite V2 is a white LED Board with boosted red spectrum. Each Board is powered by 64 high power white LED, 16 630nm Red LED and 16 660nm Deep Red LED.” If they’re the same reds in the qb35, then specs can be found here: https://www.luminus.com/products/horticulture

My hlg qb35s have four 730s, six 660s, and eight 630s; so i’m thinking about 8 or so 730s per qb96.

I can’t believe they didn’t substitute a few 730s fot the other reds, but the silver lining is that with separate far reds you can run the far reds in a less complicated manner to get both emerson and initiator - run fr full lightson plus x minutes....

Thanks man!

I would also go with up to 8 additional far-red diodes per 96Elite to get a 2:2:1 ratio. But you need to know how much current each red and deep-red diodes get. If they only run with 150mA when fully ramped up you would only need 4
XP-Es at 300mA to get the desired 2:2:1 ratio.
I have not looked at the internal circuitry of the QB96 and do not know how much current each diode gets. The Nichias are 6v diodes as far as I know and can be operated on over 4w. Possible that each string runs with up to 500 or 600mA.
To finally figure out how much far-red diodes are needed we need to know how much current the red and deepreds on QB96 can get. It would be sufficient to know how many watts there are of each wavelength.

With far-red it's such a thing ..
Few peeps swear on it and love it, others do not believe in it and don't like it at all.
I think it will take a while for it to get widely accepted and until then we'll have to add it ourselves.
Almost similar to CRI80 and 90. Some believe in efficiency other prefer a better spectrum.

Producers like HLG must take this into account and decided to make products for both of this peeps.
Currently if someone wants far-red he has to add it himself but I'm pretty sure we will soon see more and more products with build-in far-red.
I must say, I like my far-red on a separate driver because this way I can use it for EoD treatment and when lights on. With build-in far-red diodes one would need a separate flower-trigger or at least discrete internal circuits to be able to use it for supplemental lighting "and" EoD treatment.

I'll take a closer look at the QB96. Maybe I can find information about the internal circuits. If not, we have to ask HLG at how much current the diodes are running.

 

[Aolelon]

I thought the emerson effect was brought on with 680nm and 700nm. The report says the more you go over 700nm the more the effect rapidly declines.
"Emerson, and follow up research in the early 60's, all acknowledged that photosynthesis drops off VERY rapidly above 700nm (see Figure 1 in this paper by Emerson), and quantum yield at 710nm is typically charted around 10% or less of quantum yield at 660nm, and 1% at 720. It tails off to a negligible number beyond that"
https://www.reddit.com/r/Head2HeadMG/comments/2nt3hu/far_red_light_the_emerson_effect_and_phytochrome/

 

[Randomblame]

I thought the emerson effect was brought on with 680nm and 700nm. The report says the more you go over 700nm the more the effect rapidly declines.
"Emerson, and follow up research in the early 60's, all acknowledged that photosynthesis drops off VERY rapidly above 700nm (see Figure 1 in this paper by Emerson), and quantum yield at 710nm is typically charted around 10% or less of quantum yield at 660nm, and 1% at 720. It tails off to a negligible number beyond that"
https://www.reddit.com/r/Head2HeadMG/comments/2nt3hu/far_red_light_the_emerson_effect_and_phytochrome/

With 680 and 700nm the effect is the strongest but the effect is also detectable in other combinations. 630 and 710, 660 and 730nm for instance. 730nm is used because there are no 700nm diodes to date but also when 730nm not drives photosyntesis directly it switch phytochromes "on and off" and drives the emerson effect. If you look at the XP-E datasheet you can also see that a far red diode produce light in the range from 680nm to 750nm so a part of its light fits perfectly.

 

[devile]

My marsII400 works well, but I noticed two pcs of leds are very dim, is it IR?

 

[Randomblame]

My marsII400 works well, but I noticed two pcs of leds are very dim, is it IR?
View attachment 4214325

Yepp, if they look reddish it should be far-red. IR is 840 or 940nm and is almost pure heat and more or less useless for plants.

 

[Or_Gro]

I would also go with up to 8 additional far-red diodes per 96Elite to get a 2:2:1 ratio. But you need to know how much current each red and deep-red diodes get. If they only run with 150mA when fully ramped up you would only need 4
XP-Es at 300mA to get the desired 2:2:1 ratio.
I have not looked at the internal circuitry of the QB96 and do not know how much current each diode gets. The Nichias are 6v diodes as far as I know and can be operated on over 4w. Possible that each string runs with up to 500 or 600mA.
To finally figure out how much far-red diodes are needed we need to know how much current the red and deepreds on QB96 can get. It would be sufficient to know how many watts there are of each wavelength.

With far-red it's such a thing ..
Few peeps swear on it and love it, others do not believe in it and don't like it at all.
I think it will take a while for it to get widely accepted and until then we'll have to add it ourselves.
Almost similar to CRI80 and 90. Some believe in efficiency other prefer a better spectrum.

Producers like HLG must take this into account and decided to make products for both of this peeps.
Currently if someone wants far-red he has to add it himself but I'm pretty sure we will soon see more and more products with build-in far-red.
I must say, I like my far-red on a separate driver because this way I can use it for EoD treatment and when lights on. With build-in far-red diodes one would need a separate flower-trigger or at least discrete internal circuits to be able to use it for supplemental lighting "and" EoD treatment.

I'll take a closer look at the QB96. Maybe I can find information about the internal circuits. If not, we have to ask HLG at how much current the diodes are running.

Thanks RB, i’ll try to get some add’l info from hlg on the diodes.

I assume for now that they are using the same red and deep red diodes in the 96 as in the 35. So i can also try to come at it from a spectrum-matching perspective, putting in enuff fr to match the dr and fr peaks in the first spectrum above. My growbright fr bar has about 30 diodes, so would be close to amount needed for a set of four 96s (although i believe the growbright diodes are 740s, so maybe i need a growmau puck).

How many fr diodes in the rapidled-growmau5 puck?

 

[Randomblame]

If looked around for some more info and it seems the 96elite can run actively cooled with up to 6,4amps. There are 8 parallel strings, each string has 8 white + 2 red + 2 deep red diodes and can run with 800mA(limit from red/deep red diodes, white diodes can work with 1,5amps). Passively cooled they run with 4,2amps so each string gets 525mA.

You could either use 8 far-reds and a 525mA driver or you run two parallel strings of 4 diodes on a 1050mA driver. But you could also use only 6 far-red diodes and drive them at 700mA to get zhe desired 2:2:1 ratio.

 

[Or_Gro]

If looked around for some more info and it seems the 96elite can run actively cooled with up to 6,4amps. There are 8 parallel strings, each string has 8 white + 2 red + 2 deep red diodes and can run with 800mA(limit from red/deep red diodes, white diodes can work with 1,5amps). Passively cooled they run with 4,2amps so each string gets 525mA.

You could either use 8 far-reds and a 525mA driver or you run two parallel strings of 4 diodes on a 1050mA driver. But you could also use only 6 far-red diodes and drive them at 700mA to get zhe desired 2:2:1 ratio.

Thanks RB, i’ll probably be running them upto 4.2amps.

How many fr diodes on the puck?

 

[Randomblame]

Thanks RB, i’ll probably be running them upto 4.2amps.

How many fr diodes on the puck?

These growmau5 puks each have 4 diodes running at 700mA. Would be a 2:2:0,75 ratio with one of them or 2:2:1,5 with two puks. I would start with one and add another one later if you have the feeling it could be more.