3000k to Red to Far Red Ratio

[Have2]

I'm trying to figure out the best ratio from white to red to far red.

Using :

SI-B8VZ91B20WW

Samsung Semiconductor

LED MOD FSERIES GEN3 3000K STRIP

Running 12 strips on 2x HLG-480H (5x5 coverage)

Supplemental:
Cree XP-E2 660 nm diodes (20 diodes on each strips)
Cree XP-E2 730 nm diodes (20 diodes on each strips)

Planning on adding 3 strips of 660 and 3 strips of 730 to get better coverage.
Driving the 660-730 on HLG-240H

What would be the best ratio to use? I was using it with the same % so if the 3000K were dimmed at 50% I used to dim the reds at 50% but discovered that it was adding 150 PAR with red only, which is kinda high amount since the 3000k has some red in it. Almost 20% of the total PAR was from the reds (660/730).

What would you aim? Also, what would you use Red vs Far Red? If using 100% of Red, 50% of far red? 25? 75?

I'm lost!

thanks for any help!

 

[Rocket Soul]

If youre adding more than say 20-25% 660 then i would just forget about the white and just focus on red to far red ratios.
Have a look at 4000k and 5000k 80 cri spectrums: they contain 20% and 25% blue, a big serious spike and much stronger than the red you see in standard 3000k. So if there is so little red in 3000k comparatively the main concern is just getting your supplement rates right. Here you can try 3:1 or 4:1 of 660/730. Both have been tried and documented somewhere without major negative results. If youre adding some uv or a sub 450nm source of blue maybe you could use even more far red.

Have a look at this thread: https://www.rollitup.org/t/growdown-mars-hydro-vs-grow-lights-australia.1076599/

And in general anything about the highlight 420, theyve done a lot of testing to get their spectrum to where it is.

 

[Have2]

If youre adding more than say 20-25% 660 then i would just forget about the white and just focus on red to far red ratios.
Have a look at 4000k and 5000k 80 cri spectrums: they contain 20% and 25% blue, a big serious spike and much stronger than the red you see in standard 3000k. So if there is so little red in 3000k comparatively the main concern is just getting your supplement rates right. Here you can try 3:1 or 4:1 of 660/730. Both have been tried and documented somewhere without major negative results. If youre adding some uv or a sub 450nm source of blue maybe you could use even more far red.

Have a look at this thread: https://www.rollitup.org/t/growdown-mars-hydro-vs-grow-lights-australia.1076599/

And in general anything about the highlight 420, theyve done a lot of testing to get their spectrum to where it is.

So, let's say I put the 3000k at 50% to reach the appropriate PAR, I should dim 630 at 12% and 730 to 3 or 4%?

Another example
3000k at 85%
660 at 21%
730 at 5-7%

Trying to get more information about the shadow avoidance syndrome.. I think I'll try to keep the 730 open for few minutes after 3000k and 660 goes off.

Thanks!

 

[Have2]

@Rocket Soul

Just for the fun of it...
I have few questions.... or interrogations

We often see that when growing using leds, that we need to raise room temp to keep the same photosynthesis rate since led has less IR vs HPS.

But how about the 660-730 leds? Do they raise leaf temp? If yes, that's a massive playfield to play around if we dim/change the R/FR ratio along the way. I have an infrared thermometer, pure crap... I borrowed a thermal camera and the infrared thermometer was showing 4-5 F less than the IR thermometer... 4-5F is a massive difference in leave temp! I have more confidence in a 1500$ thermal camera vs 20-30$ ir thermometer... But can't borrow it each time I am playing around and it's a big expense to be fooling around.

What are the negative points of using 1:1 ratio in the R/FR? Can this causes foxtail? herm or other plant issues?


Welcome anyone to this open discussion! We are here to learn!

 

[Rocket Soul]

So, let's say I put the 3000k at 50% to reach the appropriate PAR, I should dim 630 at 12% and 730 to 3 or 4%?

Another example
3000k at 85%
660 at 21%
730 at 5-7%

Trying to get more information about the shadow avoidance syndrome.. I think I'll try to keep the 730 open for few minutes after 3000k and 660 goes off.

Thanks!

So i was writing something previously then you hit me with leaf surface temps:
660 , not really. It is a very efficient wave length for the photosystem. Far red yes, it can raise leaf temps a bit since it isnt very photosyntheticly efficient: a lot of energy doesnt get converted to sugars and becomes heat on the leaves.
1:1 rates. I mean you can try it but remember that as you go down thru the cannopy light gets absorbed and more far red left which can create shade avoidance and stretch.
This is a nifty link to what happens when the light goes thru the cannopy towards the bottom: basicly the left overs are green and far red:

Spectral lightmeter Gigahertz-Optik MSC15

Malocan. If you could by chance do a simple test with only a few metering points Of any difference from a fully reflective area vs anything less. Fully reflective as in white or silver floor ceiling and walls vs the normal non reflective floor and ceiling. Facing the meter up of course. Just...

www.rollitup.org

Look all your numbers are fine. However if i where to set up a similar system, with loads of extra red, id probably want a bit more blue in the mix. I would have started out at maybe 4000k and added a bunch of red. Maybe 20% of total wattage red is too much, only your plants can show you that. You mentioned you were getting 150 par (were talking ppfd, right? Or calculated numbers?) I thought this was what you wanted to add. Its a fair bit, some plants tend towards bleaching with a lot of photo red. But generally if you have a fair bit of far red you should be balancing out the two photosystems for red. Its only that 3000k + 25% red boost between both spectrums, thats a highly photosynthetic spectrum bit with one lacking thing: blue / uv for transpiration, it is what opens the stomata (together with correct environment) which allows the plant to drink and feed itself with nutes. The suggested spectrum could be hard to grow under due to requiring fairly tight margins, both for environment and nutes, which could be relieved by having some blue, or even uv on tap; they have very similar effect on the plant allthough if adding its better to add something around 400nm rather than standard 450nm, it widens the spectrum.
Or just better maybe start with those levels mentioned but try for 15% red to start with?

If you find that plants look rough and beat up, easily bleach and have poor plant "posture" as in sagging, you can try switching up a few of your strips to a higher cct (5000k, for less strips changed). It would be another way of adding blue. Anyways, you may aswell see that going in carefully with the reds you dont have any problem.

Another issue is how are you making your measurements? Just by dim position or would you use dc current meters? Dim position is probably a very unexact way depending on dimming method: pots might be fairly inexact. Better if you can measure current and watts on your dc side. Theres nifty meters for it.
Sas: bigger and slightly pale green leaves. Have you ever grown basil bought from the shop? It will arrive with nice big leaves but then the leaves get smaller and smaller as they get closer to their flower state: this initial basil was treated with far red.
Another thing about far red/sas is that it lowers the levels of light the plant can handle.
Id suggest making tests yourslef cause your grow style and some strain dependance will also play in. Start with less.

 

[Have2]

So i was writing something previously then you hit me with leaf surface temps:
660 , not really. It is a very efficient wave length for the photosystem. Far red yes, it can raise leaf temps a bit since it isnt very photosyntheticly efficient: a lot of energy doesnt get converted to sugars and becomes heat on the leaves.
1:1 rates. I mean you can try it but remember that as you go down thru the cannopy light gets absorbed and more far red left which can create shade avoidance and stretch.
This is a nifty link to what happens when the light goes thru the cannopy towards the bottom: basicly the left overs are green and far red:

Spectral lightmeter Gigahertz-Optik MSC15

Malocan. If you could by chance do a simple test with only a few metering points Of any difference from a fully reflective area vs anything less. Fully reflective as in white or silver floor ceiling and walls vs the normal non reflective floor and ceiling. Facing the meter up of course. Just...

www.rollitup.org

Look all your numbers are fine. However if i where to set up a similar system, with loads of extra red, id probably want a bit more blue in the mix. I would have started out at maybe 4000k and added a bunch of red. Maybe 20% of total wattage red is too much, only your plants can show you that. You mentioned you were getting 150 par (were talking ppfd, right? Or calculated numbers?) I thought this was what you wanted to add. Its a fair bit, some plants tend towards bleaching with a lot of photo red. But generally if you have a fair bit of far red you should be balancing out the two photosystems for red. Its only that 3000k + 25% red boost between both spectrums, thats a highly photosynthetic spectrum bit with one lacking thing: blue / uv for transpiration, it is what opens the stomata (together with correct environment) which allows the plant to drink and feed itself with nutes. The suggested spectrum could be hard to grow under due to requiring fairly tight margins, both for environment and nutes, which could be relieved by having some blue, or even uv on tap; they have very similar effect on the plant allthough if adding its better to add something around 400nm rather than standard 450nm, it widens the spectrum.
Or just better maybe start with those levels mentioned but try for 15% red to start with?

If you find that plants look rough and beat up, easily bleach and have poor plant "posture" as in sagging, you can try switching up a few of your strips to a higher cct (5000k, for less strips changed). It would be another way of adding blue. Anyways, you may aswell see that going in carefully with the reds you dont have any problem.

Another issue is how are you making your measurements? Just by dim position or would you use dc current meters? Dim position is probably a very unexact way depending on dimming method: pots might be fairly inexact. Better if you can measure current and watts on your dc side. Theres nifty meters for it.
Sas: bigger and slightly pale green leaves. Have you ever grown basil bought from the shop? It will arrive with nice big leaves but then the leaves get smaller and smaller as they get closer to their flower state: this initial basil was treated with far red.
Another thing about far red/sas is that it lowers the levels of light the plant can handle.
Id suggest making tests yourslef cause your grow style and some strain dependance will also play in. Start with less.

Yes, 150 PAR (ppfd measured with an apogee MQ-610 (340-1040 nm - extended range)). Reading what you are saying, I think I'll lower the Red/Fr at your suggested rate.. Red at 15% of the 3000k and a ratio red/fr of 3.5-4. I'm thinking about dropping one strip, would be 5 strips for each hlg-480h instead of 6. I put 10 strips (for a 5x5) but added one strip on each side of the fixture to balance the average PPFD. But even at 85% of the 3000k, I'm having a hard time reaching 1000 PAR without getting really close to the strips. So going with 5 strips, 1/6 strips less to drive. I'll see how it goes or maybe compare one without side strips and one with and check the numbers. My last crop was great, green leaves, no bleaching... Even if I was going with a lot of red! First run with the reds, I had them at the same % of the 3000k. LOL (it was gigantic!) but had a lot of foxtail, so I'm wondering if that kind of unbalance can causes this kind of growth. I'm using a trolmaster and lma-14 to dim (0-10v) so both should be properly balanced. I measured using a watt meter and when I was at 50%, 60%, 70%, the numbers on the watt meter was matching the change in %. Also, I can play with the dim and compare with the apogee just to make sure.

"Another thing about far red/sas is that it lowers the levels of light the plant can handle." ooooo! That's maybe the reason I cannot go over 850-900 ppfd without seeing weird thing happening.

And you're horrible! Now you make me wanna buy some blue/uv supplements! I have a UVA from HLG on hand, I'll compare... I'll try getting one or two blue supplemental bar also, just to test... Any blue strip you'd recommend? Or simply switch some strips to get 4k, maybe it would be ideal... Damn I love growing!

As for basil, no, never try, maybe I should! I though about strawberries also, it would be nice to grow that fruit!

 

[Rocket Soul]

Yes, 150 PAR (ppfd measured with an apogee MQ-610 (340-1040 nm - extended range)). Reading what you are saying, I think I'll lower the Red/Fr at your suggested rate.. Red at 15% of the 3000k and a ratio red/fr of 3.5-4. I'm thinking about dropping one strip, would be 5 strips for each hlg-480h instead of 6. I put 10 strips (for a 5x5) but added one strip on each side of the fixture to balance the average PPFD. But even at 85% of the 3000k, I'm having a hard time reaching 1000 PAR without getting really close to the strips. So going with 5 strips, 1/6 strips less to drive. I'll see how it goes or maybe compare one without side strips and one with and check the numbers. My last crop was great, green leaves, no bleaching... Even if I was going with a lot of red! First run with the reds, I had them at the same % of the 3000k. LOL (it was gigantic!) but had a lot of foxtail, so I'm wondering if that kind of unbalance can causes this kind of growth. I'm using a trolmaster and lma-14 to dim (0-10v) so both should be properly balanced. I measured using a watt meter and when I was at 50%, 60%, 70%, the numbers on the watt meter was matching the change in %. Also, I can play with the dim and compare with the apogee just to make sure.

"Another thing about far red/sas is that it lowers the levels of light the plant can handle." ooooo! That's maybe the reason I cannot go over 850-900 ppfd without seeing weird thing happening.

And you're horrible! Now you make me wanna buy some blue/uv supplements! I have a UVA from HLG on hand, I'll compare... I'll try getting one or two blue supplemental bar also, just to test... Any blue strip you'd recommend? Or simply switch some strips to get 4k, maybe it would be ideal... Damn I love growing!

As for basil, no, never try, maybe I should! I though about strawberries also, it would be nice to grow that fruit!

To be honest it looks like you have things fairly under control : if it aint broke then why fix it. No matter what all the theory is you always need to start by looking at your plants. If theyre growing happily then your good.

Sorry about getting you all riled up about blues and uv. I encourage you to try and work out what works for you. If your plants have transpiration boner for most of the grow: leaves reaching for the light, instead of sagging then you dont really have a problem if you want to add blue try to use diodes which add something new: not standard 450nm but something lower, between 420 and 380nm. I know kingbrite on alibaba have stuff like this. A good compromise between diode efficiency and spectrum would be around 400nm: these diodes are efficient and fairly easily obtainable. Adding blue thru higher cct white strips: id go all the way down to 5000k and have these strips grouped in one wago so you can add it and remove it from the spectrum by connecting and disconnecting them from the driver. You could even have a switch for it on the dc side, get a standard light switch from your hardware/electrician if you like. You seem very into experimenting, just go with it, it makes the experience better and everytime you have a new tool you learn new things. Just be careful cause sometimes it gets too much, to many details to control. Id suggest reading up on plant response: theres a blue response, green response, red response and then sas which is like a subsection of the red response. Id also suggest that there is a "blurple" response which may be usefull aswell but mainly in starting the grow, not really for flower. Tailor your setup so you can play with these responses in an easy way, i wouldnt put each wavelength diode on its own driver cause it becomes a mess.


Far red/sas : this isnt allways the case, tbh honest i think growing under 900-1000ppfd is not that easy especially if you have the whole cannopy in that intensity. It might not be the far red, just a lot of light.

I will not be off from the forum for some time so best of luck.

 

[Have2]

To be honest it looks like you have things fairly under control : if it aint broke then why fix it. No matter what all the theory is you always need to start by looking at your plants. If theyre growing happily then your good.

Sorry about getting you all riled up about blues and uv. I encourage you to try and work out what works for you. If your plants have transpiration boner for most of the grow: leaves reaching for the light, instead of sagging then you dont really have a problem if you want to add blue try to use diodes which add something new: not standard 450nm but something lower, between 420 and 380nm. I know kingbrite on alibaba have stuff like this. A good compromise between diode efficiency and spectrum would be around 400nm: these diodes are efficient and fairly easily obtainable. Adding blue thru higher cct white strips: id go all the way down to 5000k and have these strips grouped in one wago so you can add it and remove it from the spectrum by connecting and disconnecting them from the driver. You could even have a switch for it on the dc side, get a standard light switch from your hardware/electrician if you like. You seem very into experimenting, just go with it, it makes the experience better and everytime you have a new tool you learn new things. Just be careful cause sometimes it gets too much, to many details to control. Id suggest reading up on plant response: theres a blue response, green response, red response and then sas which is like a subsection of the red response. Id also suggest that there is a "blurple" response which may be usefull aswell but mainly in starting the grow, not really for flower. Tailor your setup so you can play with these responses in an easy way, i wouldnt put each wavelength diode on its own driver cause it becomes a mess.


Far red/sas : this isnt allways the case, tbh honest i think growing under 900-1000ppfd is not that easy especially if you have the whole cannopy in that intensity. It might not be the far red, just a lot of light.

I will not be off from the forum for some time so best of luck.

Thanks for your help! Really appreciated!
I'm anxious to restart with adjusted red/fr ratio!

As for the 900-1000ppfd... I don't know, a lot of research went even at 1500 and sometimes more and I have everything else under control.

Enjoy your holidays!