630nm:660nm ratio?

Been in analysis paralysis mode on choosing possible spectrums for a potential customized panel from either Cidly or Bysen (finally got a response, they do custom!). I've read some suggestions that the 630nm:660nm ratio in a grow light should be roughly 2:3, but that's with some other colors thrown in the mix. Right now, neglecting the other colors for the sake of discussion, why would we want more 660nm than 630nm? Seems it should be the other way around. Can anyone shed light on this subject?

In addition, I see a trend with no actual 630nm, just a mix of CW or WW with 660nm, with the whites contributing to the 630nm.

Thanks!

EDIT: Consideration is for a flowering panel only, I have seen the study on tomatoes where it seems the best 400-500nm:500-600nm:600-700nm ratio is 10:15:75 but that doesn't really specify the differences on using 660nm and 630nm.

without seeing the spectral distribution of the actual brand LED you're choosing from it's hard to tell. Each LED brand(not light manufacturer) has their own rise/fall on the graph.

This is the 4-band Kessil graph

Note the bigger bump on 660 than 630.

This is the California Light Works spectrum

Again, more 660 than 630.

Here's Apache Tech's


Whites + Reds, but peak in the 630-640nm

Yes, all things considered, I'm not talking about total overall spectrum, but the ratio of 630nm to 660nm.

https://www.rollitup.org/led-other-lighting/672979-deep-red-around-660nm-yay.html

I personally dont think it matters that much as long as they're roughly equal. Its just about spreading the spectral output in my opinion. If anything i would go slightly more 630 than 660, unless you are overpowering your grow area, in which case the other way round. Probably an academic distinction though since red light is so low energy.

In spectral charts of the sun in autumn, it looks like there is definitely more in the lower reds than 660nm and there abouts. Of course we aren't trying to necessarily mimic the sun because of all the green we'd be using, and this is artificial light as well. Still I think that it would be safer (just a wild guess to stick with a sun-type curve in the red zone with more 630-640nm than 660-670nm.

Basically all my experience is with no direct 660nm...apaches, and they work great. I had a stealth a while back before I knew anything and was unsatisfied and sold it, but I don't count that cause I sucked too so it's a wash. But I do think that 660 would be a bad thing but I do not agree that it needs to be dominant. If I were to make a panel using both reds I would do it at only 3:1 or 4:1, maybe even 5:1, 630nm to 660nm...definitely less than 25% of the red value being from direct 660. And when using whites hitting the 630 range and broader, not much pure red is needed. Somewhere between 3:2 and 4:1, white(everyone uses a different temp) to red(630nm) has been showing great results from multiple companies and supplying low yet sufficient amounts of 660nm, but a little more wouldn't hurt IMO.

professional light spectrum...


estimated Ratio 630/660 - 1:5

After studying this to death, I don't think 660nm in greater amounts -- or exclusively for reds -- is a good thing overall. Perhaps some LED manufacturers have it, but we're still growing a plant that is used to getting more in the 630nm region than the 660nm region, both outdoors and with artificial lighting. So I am really thinking that it would be better to focus on 630nm over 660nm, but not to exclude the latter. Then it might be beneficial to throw in a very small amount of 730nm for the Emerson effect. Using this as a basis, my latest target ratio is going to be 5 CW: 7 630nm : 2 660nm: 1 730nm.

Be vary careful putting actual FR diodes in the mix bro, seen a couple of grows where they caused some problems (because of the quantity of FR). maybe on a seperate switch/dimmer??

SnotBoogie said:

Be vary careful putting actual FR diodes in the mix bro, seen a couple of grows where they caused some problems (because of the quantity of FR). maybe on a seperate switch/dimmer??

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Yeah, I've been really debating this. The 730nm would be one 3w LED per 15 piece module (or just one of 21 on another). The reason for the 730nm would be to make more use of the 660nm, if that is what I glean from the Emerson effect thing. I've even seen a few say that you shouldn't have 660nm without some 730nm, but I think that was just personal experiences without thorough study of the matter. I'm on the fence with it right now, but I'd probably just put another red chip in its place.

I do want to throw some 660nm in the mix.

Sb, thanks for making me look more closely at this. From what I can gather, there are two different things (at least) we can do with 660nm and 730nm. One is the Emerson effect, something that I am not sure is all that true. I'm going to be looking into that.

The other is phytochrome manipulation, but this does not work when the 660nm and 730nm are on at the same time. In fact, many hypothesize that the opposite is true. If this is the case, having both in my mix is not a good idea for a bloom panel. Again, from what I've read, feel free to show me I'm wrong because I'm learning.

So the 730nm is out for now.

Hans uses some 660nm (or thereabouts) in his panel and people rave over it for such a low wattage fixture. Not much mind you but he seems to think it works.

Who here gets good results using much more 660nm than 630nm?

I use a little more 660 than 630. Not that i planned to, just how my panels came together lol.

The Pr/Pfr (phytochrome response) cycle is what i would utilise 730nm for (15min of FR before lights off). to expand on what i meant by using "exclusively FR" diodes is that Whites will have marginal amounts of FR in them too, probably enough.

Just to also restate, i dont think it matters "too much" on the precise ratio of 630/660 and everything in between. "I think" most important is simply spreading your spectra around that range. Just my take on it though. Also dont forget that "monochromatic" LEDs will still have a ~20nm wide band of emission.

I thought Emerson was at 670+700? And Brother J have you found the study yet that shows 670nm inhibits flowering? Love that one. I think it's in Rosenthal's last book. That'll keep the paralysis going. LOL

+1 for heavy 660nm in flower. Here's a panel that I just retired because of electrical consumption but thought you might like to hear a little about it. It's a LED Star 5x60 and it's 30x660nm, 10x730, 5x10,000K, and 5x4200K and it was a pretty good flowering panel. Great for getting my plants to finish which is something my duall BS240s never seemed to do. Unfortunately the diodes used are woefully inefficient and have to be run at lower mA (630) because of the heat they generate. I'm either rebuilding it and making multiple smaller panels or getting something new, which is what I should do. Anyway 730's not just for Emerson though, and probably doesn't contribute much IMO, but has anyone really done a proper study on the Emerson effect with LEDs and marijuana? To me I like 730nm for phytochrome production, stimulating root growth and basically getting your plants to drink more which is why I won't flower without some FR/IR. How much is right? Who really knows. There just hasn't been enough time with LED growing to know but I like what goes on in my tent with it.

Bottom line, fuck ratios. Get the best panel you can find and afford and use it. Like what you have? Great. Don't like? Then start over or start adding lights/panels. Look at your space. Light your space. Then tweak your space. Overall nobody knows dick about growing marijuana with LEDs yet and anyone who says they do should be held under the highest scrutiny. Maybe some folks at UMISS and a handful of others but that's about it.

So Good Luck BrotherJ. You really should open a dialog with Apache Tech. They probably have some information for you. They seem to be the panel manufacturer with a more scientific pedigree, though I do like A51 cause I feel there's a little more practical knowledge about growing marijuana in EH's product.

Yeah, the problem is that not all plants react the same. I can see what increasing FR does for tomatoes, but MJ is not a tomato. I'm not ready to get into the FR at the end of the 12h day yet, I still want to keep things simple. Lights on, lights off. Sure, the other is a matter of another light or two on a different timer, but I'm focusing on what should go into my next panel.

The problem with potentially adding too much far red in my bloom panel is that I could increase my stretch by a bit, which is what I like to avoid. But once stretch is over, throw in the far red. Again, this is not practical with my set-up for various reasons.

Right now I use an OK PG180 on one side and ~156w of 2700-3000k PLLs on the other. I like to finish my plants under the PLLs because, theoretically, they have a bit more red than blue, green, etc. than my PG180. But sometimes my grows don't cooperate and I simply must use whatever space is available, and some plants start under the PLLs rather than finish.

That being said, I can always mix up the whites between CW and WW. Was aiming for 10% blue from using all cools, mostly to help inhibit stretch. On the flip side, the WW would lend a little more FR of its own, perhaps enough to bump up yield. So its a balancing act right now, and all hypothesis based on the knowledge I've been picking up.

^^^^^ I think those Greeks over at astir may know what's going on more than any of us with leds and mj....


I use 730-760 all through flower with t5. I like it ... starts flowering at day 8. So strains are done a week to half a week earlier than normal. Still chunk up the same. But definitely more dense.

There's an article in urban garden where it says chlorophyll absorbs 75% of light from 650 - 700

Do you use the FR during the stretch phase?

I use IR all through flower. It aids in flowering sooner and drives flowering and controls density. There's IR effects on plant studies at Texas A&M and Washington State. But I don't run IR after lights out to move into pfr state faster. At the end of summer and through fall IR is there all day not just when the sun sets. Parts of the world there is IR year round. Like Hawaii. You have to veg indoors there because mj flowers year round. Some people start seeds in the dark shade there out of direct sunlight. When the sun is completely down its dark. I think to truly imitate nature you would have to dim different wave length at different rates and recreate moon light and stars... Imo the 730 pfr light is pointless.

Cool thread as I've been neck deep in this whole ordeal for some time, and on the far red aspect of the convo I have seen vast improvement on my flowering times and production with just the addition of two lumi grow far red bulbs (pricey wont lie) but well worth it. I have them come for an hour in two intervals (after some trial an error) they turn on a half hour before lights on and stay on for another half hour ....than they turn on a half hour before lights out and stay on for a half hour in darkness, while my lights stay on for 12/12 the first couple weeks of flower than bumped up to 13/11 for four weeks, followed by 12/12 last couple of weeks and my flower times on any strain indica or sativa dominant finish up bulkyyy and ready a week to a week and a couple days faster than before I ever had the far red supplementation with an honest better yield. But with only dishing out 34 watts total of far red for two hours a day its well worth it to me. And thats based on my room with 3k hids....I have a separate room with 6 area 51 sg-160 panels with the same far red timing and had the same success.
On the 630/660nm ratio discussion I am fixing my dead apollo 16 led unit with all new modules containing 630nm:660nm:6500k exact ratio of 5:5:5 in all clusters so i will see how that works out for flowering as well compared to the first array I had with the traditional 7 spectrum they came with...I love my sg-160s with just 4000k and 630 red so im curious what my new apollo will do....sorry for the long ramble on just wanted to throw my hat into the ring

Inhibits or enhances flowering? I'd certainly not want the former. Not considering the FR after lights off at all right now, just wondering what effect FR has during all stages of flowering. The FR can be there during stretch, but how much blue would you need to counteract the presence of it? If I'm moving from 6500k for veg into a spectrum with much more red, I expect stretch. But tossing in the FR to an amount that exceeds what it came from by quite a bit might make the plants want to stretch even more than if I leave it out.

By vegging under 6500k for a total of 18 hours, I'm already creating an environment that is nothing like the sun, so I'm not concerned with mimicking during bloom. I just want a good spectrum that a) gives good yields and b) does not create more of a stretch than I already experience.

Cococola36 said:

Cool thread as I've been neck deep in this whole ordeal for some time, and on the far red aspect of the convo I have seen vast improvement on my flowering times and production with just the addition of two lumi grow far red bulbs (pricey wont lie) but well worth it. I have them come for an hour in two intervals (after some trial an error) they turn on a half hour before lights on and stay on for another half hour ....than they turn on a half hour before lights out and stay on for a half hour in darkness, while my lights stay on for 12/12 the first couple weeks of flower than bumped up to 13/11 for four weeks, followed by 12/12 last couple of weeks and my flower times on any strain indica or sativa dominant finish up bulkyyy and ready a week to a week and a couple days faster than before I ever had the far red supplementation with an honest better yield. But with only dishing out 34 watts total of far red for two hours a day its well worth it to me. And thats based on my room with 3k hids....I have a separate room with 6 area 51 sg-160 panels with the same far red timing and had the same success.
On the 630/660nm ratio discussion I am fixing my dead apollo 16 led unit with all new modules containing 630nm:660nm:6500k exact ratio of 5:5:5 in all clusters so i will see how that works out for flowering as well compared to the first array I had with the traditional 7 spectrum they came with...I love my sg-160s with just 4000k and 630 red so im curious what my new apollo will do....sorry for the long ramble on just wanted to throw my hat into the ring

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Dead Apollo eh? What happened?