OneHitDone
Well-Known Member
In you opinion with the current diode offerings, how closely could you replicate the Wavelength Distribution %'s of HPS? Think it can be done "Efficiently"?
Catch me up
- Thread starter Rahz
- Start date
hybridway2
Amare Shill
We're getting much better off other spectra. Why bother?
OneHitDone
Well-Known Member
Cause Cal-Mag and excess runoff bro. You know even the "best" in led spectra falls short in plant health
Grow Lights Australia
Well-Known Member
You'll forgive me if I think that's a strange question – why wouldn't you just use a DE HPS? They are around 2 umol/j these days. Also, the Cal-Mag issues some growers appear to have with LED is due to running lower temperatures which has nothing to do with spectrum. Most issues appear to be due to lower leaf transpiration or rates of evaporation at the root zone (typical overwatering symptoms) so I don't see how running a LED with the same spectrum as a HPS is going to fix that.
None of our test growers are having any real issues growing under LED. As you know, @Prawn Connery does testing for us and he posted some photos of a test-grow below which he said were some of the best he has vegged under LED. He said he had never had any trouble flowering under LED. None of our test growers have had issues flowering and all that have switched from HPS have had outstanding results. These are guys who nearly all grow in coco so perhaps they are already feeding the correct amount of Cal-Mag to begin with or maybe they just know how to grow.
After talking to a few growers who switched to LED in veg most reported better results running lower light levels or more balanced spectra such as 3500-4000K instead of 5000+K. Our theory is the high kelvin temperature LEDs have a lot of blue light in them which saturates the plants leading to light stress if it is not photosynthesised. Blue light carries more energy and blue photons that are not photosynthesised cause leaf temps to rise which can lead to bleaching. 5000K LEDs have much more blue light in them than traditional CMH or HPS and I think contrary to popular belief, while blue light is responsible for stomata opening and higher levels of transiration, too much of it is detrimental. That is why you often see leaf edge curling, which is a sign of a plant trying to accelerate transpiration to cool down even though there is an abundance of blue light. It is actually excessive blue light that is causing the increase in leaf temperatures to begin with.
So in a way I have just come full circle to agree with you
But for different reasons. What I am also saying is that if you have a balanced spectrum to begin with you should not be having any issues. As long as you do not go too hard on the light. We often have to explain to HID growers that LED is much more powerful than it appears and that "less is more" when it comes to growing. These are growers who do bleach their plants or suffer nutrient deficiencies primarly because they are running the lights too close or running too much light in their grow area.With apologies to @Rahz for hijacking his thread. Sorry.
OneHitDone
Well-Known Member
I was not speaking from a Cal-Mag point of view but agree with pretty much everything you have said here. You guys are doing solid work and I applaud the fact that you are going way outside the box with your lights.You'll forgive me if I think that's a strange question – why wouldn't you just use a DE HPS? They are around 2 umol/j these days. Also, the Cal-Mag issues some growers appear to have with LED is due to running lower temperatures which has nothing to do with spectrum. Most issues appear to be due to lower leaf transpiration or rates of evaporation at the root zone (typical overwatering symptoms) so I don't see how running a LED with the same spectrum as a HPS is going to fix that.
None of our test growers are having any real issues growing under LED. As you know, @Prawn Connery does testing for us and he posted some photos of a test-grow below which he said were some of the best he has vegged under LED. He said he had never had any trouble flowering under LED. None of our test growers have had issues flowering and all that have switched from HPS have had outstanding results. These are guys who nearly all grow in coco so perhaps they are already feeding the correct amount of Cal-Mag to begin with or maybe they just know how to grow.
After talking to a few growers who switched to LED in veg most reported better results running lower light levels or more balanced spectra such as 3500-4000K instead of 5000+K. Our theory is the high kelvin temperature LEDs have a lot of blue light in them which saturates the plants leading to light stress if it is not photosynthesised. Blue light carries more energy and blue photons that are not photosynthesised cause leaf temps to rise which can lead to bleaching. 5000K LEDs have much more blue light in them than traditional CMH or HPS and I think contrary to popular belief, while blue light is responsible for stomata opening and higher levels of transiration, too much of it is detrimental. That is why you often see leaf edge curling, which is a sign of a plant trying to accelerate transpiration to cool down even though there is an abundance of blue light. It is actually excessive blue light that is causing the increase in leaf temperatures to begin with.
So in a way I have just come full circle to agree with you
With apologies to @Rahz for hijacking his thread. Sorry.
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What I was referring to was a more Orange centric spectrum with the IR end toned down from what an HPS actually is.
I have seen the same varieties grown under Sun, HPS, and MH lamps and what HPS does to the flower structure is unmistakable. Just thinking to myself that adding the big red spike in all of these current led's on the market may actually be going in the wrong direction
Warpedpassage
Well-Known Member
Are these plants under the new boards you posted about earlier on page 1 or different experiment?You'll forgive me if I think that's a strange question – why wouldn't you just use a DE HPS? They are around 2 umol/j these days. Also, the Cal-Mag issues some growers appear to have with LED is due to running lower temperatures which has nothing to do with spectrum. Most issues appear to be due to lower leaf transpiration or rates of evaporation at the root zone (typical overwatering symptoms) so I don't see how running a LED with the same spectrum as a HPS is going to fix that.
None of our test growers are having any real issues growing under LED. As you know, @Prawn Connery does testing for us and he posted some photos of a test-grow below which he said were some of the best he has vegged under LED. He said he had never had any trouble flowering under LED. None of our test growers have had issues flowering and all that have switched from HPS have had outstanding results. These are guys who nearly all grow in coco so perhaps they are already feeding the correct amount of Cal-Mag to begin with or maybe they just know how to grow.
After talking to a few growers who switched to LED in veg most reported better results running lower light levels or more balanced spectra such as 3500-4000K instead of 5000+K. Our theory is the high kelvin temperature LEDs have a lot of blue light in them which saturates the plants leading to light stress if it is not photosynthesised. Blue light carries more energy and blue photons that are not photosynthesised cause leaf temps to rise which can lead to bleaching. 5000K LEDs have much more blue light in them than traditional CMH or HPS and I think contrary to popular belief, while blue light is responsible for stomata opening and higher levels of transiration, too much of it is detrimental. That is why you often see leaf edge curling, which is a sign of a plant trying to accelerate transpiration to cool down even though there is an abundance of blue light. It is actually excessive blue light that is causing the increase in leaf temperatures to begin with.
So in a way I have just come full circle to agree with you
With apologies to @Rahz for hijacking his thread. Sorry.
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Grow Lights Australia
Well-Known Member
Those plants were under a test spectrum which was tweaked for the final version. The CRI was a bit low, so we removed a little bit of blue and added a bit more green/yellow/amber by swapping some LEDs in the string. But both boards have the same amount of red and far red and are very similar. Prawn's opinion was the added far red was the key to faster, healthier growth as he noticed the leaves were bigger and broader. The reason we had a bit more blue in that test spectrum to begin with was we were not sure whether the added far red would cause undue stretch, but after seeing the results we decided we didn't need that much and it would be better to balance the spectrum. You can see in those photos the light is a bit "blurple" but that's exagerated by the camera. In real life the light had a bit of a pink tinge to it. The production boards are actually a nice crisp white with just a hint of pink.
Grow Lights Australia
Well-Known Member
One thing to remember is that generations of cannabis have been selectively grown under HPS favouring those that have given the best results, so it is no surprise that many varieties still produce well under HPS. There is one grower we work with who has a strain that is an older Skunk variety which performs consistently well under HPS compared to his other strains. The other strains appear to favour LED, so it is perhaps not as clear-cut as to which spectrum is best but rather which spectrum is best for a particular strain. But one thing is true and that is LED still generates the same or bigger yields for less energy than HPS.I was not speaking from a Cal-Mag point of view but agree with pretty much everything you have said here. You guys are doing solid work and I applaud the fact that you are going way outside the box with your lights.
What I was referring to was a more Orange centric spectrum with the IR end toned down from what an HPS actually is.
I have seen the same varieties grown under Sun, HPS, and MH lamps and what HPS does to the flower structure is unmistakable. Just thinking to myself that adding the big red spike in all of these current led's on the market may actually be going in the wrong direction
If LED manufacturers were to switch to yellower spectra then that energy advantage would probably shrink, as the most efficient LEDs at the moment are blue and red. So what you might gain in spectrum could be lost in efficiency (assuming a "HPS spectrum" is better for a particular strain). We have tried to balance spectrum and efficiency with our new lights as we know that spectrum does make a difference, however photons are still photons.
Humple
Well-Known Member
An outdoor grower, an HPS grower, and an LED grower walk into a bar...
Wait, this is the lighting jokes section, right?
Grow Lights Australia
Well-Known Member
It's only a bit of light-hearted humour
Humple
Well-Known Member
Thanks for taking it lightly.It's only a bit of light-hearted humour
Grow Lights Australia
Well-Known Member
That's alight.
SupraSPL
Well-Known Member
Whats up Rahz welcome back! Im still a COB nerd just ordered a few more 3590s 3500K DB for about $25 shipped. I will be running them somewhere between 215-245 lumens/W (3.07-3.5 umol/s/W) @10-23W ea, depending on the reality of margin of error. As far as I can tell low powered COBs can get just as even spread as the boards in practice, but more easily adaptable to canopy shape and I can quickly make custom reflectors depending on the canopy.
As far as I have seen from the datasheets so far, low powered COBs get higher efficiency, although the claim of 3+ umol/s/W from the optimized spectrum boards is very interesting work. I understand the resistance from the industry, a 150W Cob running at 10-20W is too far outside of design parameters for manufacturers to support that idea but its great for DiY. It would be funny if Cree were willing to put that data in the PCT. On some occasions I run CXB3590s as low as 3W, or even lower during power outages and it would interesting to know. Even from my own crude testing, I can see that efficiency does continue to rise significantly at low currents.
The Gen 4 Luminus are interesting COBs but the the biggest (CXM32) are based on 50V and my systems were set up for 36V so that would mean CXM27s would be swappable for me. They cost more than CXB3590s and seem to be geared for more high output rather than max efficiency, so I stuck with CXB3590s for now.
When I get them I will do some relative comparisons between CXB3590 CDs that have been running nonstop for 5 years, CXB3590 DBs that have been running for ~2 years and the brand new DBs. Maybe I will grab CXM22 CXM27 and CXM32 to add another data point for relative comparison. Im not biased toward Cree so if Luminus actually read higher at low currents I will be like Paul Revere.
As far as I have seen from the datasheets so far, low powered COBs get higher efficiency, although the claim of 3+ umol/s/W from the optimized spectrum boards is very interesting work. I understand the resistance from the industry, a 150W Cob running at 10-20W is too far outside of design parameters for manufacturers to support that idea but its great for DiY. It would be funny if Cree were willing to put that data in the PCT. On some occasions I run CXB3590s as low as 3W, or even lower during power outages and it would interesting to know. Even from my own crude testing, I can see that efficiency does continue to rise significantly at low currents.
The Gen 4 Luminus are interesting COBs but the the biggest (CXM32) are based on 50V and my systems were set up for 36V so that would mean CXM27s would be swappable for me. They cost more than CXB3590s and seem to be geared for more high output rather than max efficiency, so I stuck with CXB3590s for now.
When I get them I will do some relative comparisons between CXB3590 CDs that have been running nonstop for 5 years, CXB3590 DBs that have been running for ~2 years and the brand new DBs. Maybe I will grab CXM22 CXM27 and CXM32 to add another data point for relative comparison. Im not biased toward Cree so if Luminus actually read higher at low currents I will be like Paul Revere.
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hybridway2
Amare Shill
Guntherfredo
Member
You seem very knowledgeable on the subject do you mind telling me if you think that’s my issue every time I go about 500 actual draw my plants show signs of stress and I’m beginning to think it’s not a nutrient uptake problem itself but being pushed too much and not having enough co2 cal mag and potassium to keep up with the 500+ actual draw they are one week into stretchYou'll forgive me if I think that's a strange question – why wouldn't you just use a DE HPS? They are around 2 umol/j these days. Also, the Cal-Mag issues some growers appear to have with LED is due to running lower temperatures which has nothing to do with spectrum. Most issues appear to be due to lower leaf transpiration or rates of evaporation at the root zone (typical overwatering symptoms) so I don't see how running a LED with the same spectrum as a HPS is going to fix that.
None of our test growers are having any real issues growing under LED. As you know, @Prawn Connery does testing for us and he posted some photos of a test-grow below which he said were some of the best he has vegged under LED. He said he had never had any trouble flowering under LED. None of our test growers have had issues flowering and all that have switched from HPS have had outstanding results. These are guys who nearly all grow in coco so perhaps they are already feeding the correct amount of Cal-Mag to begin with or maybe they just know how to grow.
After talking to a few growers who switched to LED in veg most reported better results running lower light levels or more balanced spectra such as 3500-4000K instead of 5000+K. Our theory is the high kelvin temperature LEDs have a lot of blue light in them which saturates the plants leading to light stress if it is not photosynthesised. Blue light carries more energy and blue photons that are not photosynthesised cause leaf temps to rise which can lead to bleaching. 5000K LEDs have much more blue light in them than traditional CMH or HPS and I think contrary to popular belief, while blue light is responsible for stomata opening and higher levels of transiration, too much of it is detrimental. That is why you often see leaf edge curling, which is a sign of a plant trying to accelerate transpiration to cool down even though there is an abundance of blue light. It is actually excessive blue light that is causing the increase in leaf temperatures to begin with.
So in a way I have just come full circle to agree with you
With apologies to @Rahz for hijacking his thread. Sorry.
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Grow Lights Australia
Well-Known Member
Hi mate those photos look like the onset of a potassium deficiency. Are you using a lot of Cal-Mag? Because calcium can lock out potassium and I see no signs of either a calcium or magnesium deficiency. I can also see some evidence of light stress but unfortunately I don't know what light you are using over what area, so I can't tell you if 500W is too much or not, but it's possible.
Guntherfredo
Member
I’m using 2 growers choice e720 and they are stretching to close I had it set to 504 watts but I dialed it back to 435, and I’ve been feeding cal mag 2.5 ml/g, flora micro, grow, and bloom 2.5 ml/g most of the grow I tried to go up a few times, every time Ec is above 1.2, 600ppm they don’t like it and I was doing 3.75 ml/g of cal mag for a little bit but I brought it back down, the last 8 days they have been fed cal mag 2.5 ml, micro 2.5 ml, grow 1.2 ml, bloom 3.75 ml, and I’ve ran uc roots twice 3ml/5 gal, I keep tying them down they keep stretching today the closest point of the canopy was about 15 inches from the canopy they are probably 10 days into stretch, and I’ve been feeding at 550 ppm
Attachments
Grow Lights Australia
Well-Known Member
Well again, it's hard to know without proper information. What medium are you growing in? What nutrients are you using (1 or 2 part? Brand?)
It looks like you're using coco with a mix of hydroton on a flood-and-drain table. Are you top feeding with drip lines? Flood and drain is notorious for salt build-up. Also, your nutrient levels seem a bit low to me at EC1.2 and I'd be guessing you're using too much cal-mag.
You don't say what height your lights are or how big your tent is so I'm not going to guess but that light isn't all that strong so it may not be the problem.
It looks like you're using coco with a mix of hydroton on a flood-and-drain table. Are you top feeding with drip lines? Flood and drain is notorious for salt build-up. Also, your nutrient levels seem a bit low to me at EC1.2 and I'd be guessing you're using too much cal-mag.
You don't say what height your lights are or how big your tent is so I'm not going to guess but that light isn't all that strong so it may not be the problem.