LEDs and potency

I've been using CXB COBs for a small cab grow and after a few batches I just think the weed should be more potent than what it's coming out as. It's not a strain issue because I tried several different ones. You can get high off it, yeah, but I've actually had more potent stuff grown under CFLs. I don't know if it's the complete lack of UV in the LEDs or what. There's a grower with a YouTube channel (John Berfelo) who has an analyzer at home and he tested the same plant grown under HPS, CMH and LED. The HPS and LED both came out at 18% while the CMH was 22%. The only difference I could see causing that would be more UV in the CMH, or at least more blue. So anyway I have now added a 23w 6500k on each side of the top of the cab, in addition to the 240w CXB array in the middle. That's about 10w per sq ft extra. I will soon find out if it makes much difference.

BTW, something that makes me think CFL light makes more potency is that I wanted to root some cuttings from a plant that was in late flower so I put some small buds in a CFL cloning setup and after a couple days decided not to keep that strain after all so I smoked the buds and they were considerably more potent than the ones still under the LEDs. The stress of being cut off the plant may have had some effect there but it may also have been the different spectrum. LED grown buds just seem to lack something, at least the LED lamps with no UV LEDs added. I don't know about those ones. Granted there's not a huge amount of UV in CFLs either but maybe all the plants need is some, if not a lot. UV does have various effects on plants so it probably shouldn't be completely excluded as with white COB LEDs. I don't want to get actual UV lamps though, just too dangerous. I think the CFL supplementation may do the trick.

You may want to get some UV supplemental led lights.

I've read that THC is like a natural sunblock for weed and UV light stresses/damages the plant, therefore with UV light it will produce more THC to protect itself.

if you really think its better to run with CFLs over cxb cobs because of potency. Then run a side by side that shares everything except for a divider separating the light and the same wattage AND send samples out for testing..

until then please hush up. The small advantage for the cfls is a wider blue spectrum including UVA and actinic, other than that you will lose big time as the raw horsepower will outdo anything you think you are perceiving.

BobCajun said:

I've been using CXB COBs for a small cab grow and after a few batches I just think the weed should be more potent than what it's coming out as. It's not a strain issue because I tried several different ones. You can get high off it, yeah, but I've actually had more potent stuff grown under CFLs. I don't know if it's the complete lack of UV in the LEDs or what. There's a grower with a YouTube channel (John Berfelo) who has an analyzer at home and he tested the same plant grown under HPS, CMH and LED. The HPS and LED both came out at 18% while the CMH was 22%. The only difference I could see causing that would be more UV in the CMH, or at least more blue. So anyway I have now added a 23w 6500k on each side of the top of the cab, in addition to the 240w CXB array in the middle. That's about 10w per sq ft extra. I will soon find out if it makes much difference.

BTW, something that makes me think CFL light makes more potency is that I wanted to root some cuttings from a plant that was in late flower so I put some small buds in a CFL cloning setup and after a couple days decided not to keep that strain after all so I smoked the buds and they were considerably more potent than the ones still under the LEDs. The stress of being cut off the plant may have had some effect there but it may also have been the different spectrum. LED grown buds just seem to lack something, at least the LED lamps with no UV LEDs added. I don't know about those ones. Granted there's not a huge amount of UV in CFLs either but maybe all the plants need is some, if not a lot. UV does have various effects on plants so it probably shouldn't be completely excluded as with white COB LEDs. I don't want to get actual UV lamps though, just too dangerous. I think the CFL supplementation may do the trick.

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All led and cob here, damn potent! Best at my place.

BobCajun said:

I've been using CXB COBs for a small cab grow and after a few batches I just think the weed should be more potent than what it's coming out as. It's not a strain issue because I tried several different ones. You can get high off it, yeah, but I've actually had more potent stuff grown under CFLs. I don't know if it's the complete lack of UV in the LEDs or what. There's a grower with a YouTube channel (John Berfelo) who has an analyzer at home and he tested the same plant grown under HPS, CMH and LED. The HPS and LED both came out at 18% while the CMH was 22%. The only difference I could see causing that would be more UV in the CMH, or at least more blue. So anyway I have now added a 23w 6500k on each side of the top of the cab, in addition to the 240w CXB array in the middle. That's about 10w per sq ft extra. I will soon find out if it makes much difference.

BTW, something that makes me think CFL light makes more potency is that I wanted to root some cuttings from a plant that was in late flower so I put some small buds in a CFL cloning setup and after a couple days decided not to keep that strain after all so I smoked the buds and they were considerably more potent than the ones still under the LEDs. The stress of being cut off the plant may have had some effect there but it may also have been the different spectrum. LED grown buds just seem to lack something, at least the LED lamps with no UV LEDs added. I don't know about those ones. Granted there's not a huge amount of UV in CFLs either but maybe all the plants need is some, if not a lot. UV does have various effects on plants so it probably shouldn't be completely excluded as with white COB LEDs. I don't want to get actual UV lamps though, just too dangerous. I think the CFL supplementation may do the trick.

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Please check this link out, you will most likely learn something from it:

http://silassativarius.org/2014/10/03/does-exposing-your-plants-to-uvb-increase-thc-production/

Based off what I know, which is limited, most plants don't take too kindly to UVB but marijuana does. From what I've read and researched, only UVB (280~315nm) is useful, with anything lower being deadly and anything higher being useless in attempts to promote higher levels of crystals. The crystals act as mirrors and reflect the harmful UVB photons. I would reckon that having a timer for the supplemental UVB, in CFL form of course, would be your best bet as too much sun for anyone or anything can be dangerous. Maybe periodic exposure to the UVB would work best or perhaps having UVB exposure for a mere few hours per day would be enough. You will ultimately have to figure out which method works best for yourself and your plants over time.

Be sure to always wear decent sunglasses when the UVB bulbs are turned on, as you don't want to risk any sort of long-term damage to your eyes and health.

@BobCajun what temp are your COBs? 3000k?

puffenuff said:

@BobCajun what temp are your COBs? 3000k?

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They're 4000k. Anyway, it's just a little test. It's not going to be a controlled experiment or anything, just my personal taste testing to see if I think I can tell a difference. If the CFLs don't make much difference I may use blacklight CFLs, just make sure they're off before I look in there.

BTW, The 6500k CFLs were just a couple I had on hand. I got some cool whites now, probably better. CFLs are of course less efficient than LEDs but I think I can live with 46 watts in a cab. It's 5 parts LED and 1 part CFL, by wattage. If it improves potency it will be well worth it. It will also boost total wattage to a little over 60 per sq ft, which may also help.

I always use CFLs for supplemental light and extra UV.

No reason why you can't run both.

superbak3d said:

I always use CFLs for supplemental light and extra UV.

No reason why you can't run both.

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Did you also notice a lacking in potency with pure LED? Maybe it's just because I've been smoking daily for a long time, idk. Just seems like it should be more potent. There's plenty of resin but the resin apparently is lacking something, or seems to be anyway. CMH seems to produce highest potency. I just don't really want to get back into HIDs right now. I already spent a lot on the LEDs so pretty much have to use them.

That's why you just add CFLs or a reptile bulb.

I'd highly recommend anyone using LEDs to supplement with CFL or floros. You don't need much, just a little extra UV can go a long way.

The resin is what protects the plant from natural UV emitted by the sun. So obviously the higher the UV amounts the more resin production.

There's a limit though, too much UV and all that resin can burn up and your whole crop will be wasted.

Think of it like how human skin reacts to sun. High levels of UV makes us tan, but too much and burrrrrrrrn. There's also the opposite, where we can be outside in the sun all day with low UV and never burn or tan (spring/fall sun). This is where I place LED. You can be in it all day and you're not going to get burnt, or even tan.

That's why LEDs lack in the frost department. They obviously still produce resin to protect themselves from light burn, but not as much when UV is present.

So the solution is simple, just add in cfls on the sides or some floros. They'll give your buds a nice little boost in the frostiness.

Lacking in frost? Most trichs I have seen from any lights. I just looked! This is so far from what I have experienced, I just don't get it. If the trichome production was better with other lights, I would run them. Could get some tested.

Try Terpinator this run..... It wont make it more potent if you are on top your game but if you aren't it will turn out nice. It will bring out your plants genetic potential.

Its no secret intense light degrades thc, but you also you need to push photons if you want yield,so its a tradeoff,I dont think its spectrum related but I could be wrong ofc.

Ya know I always thought UVB increases THC quality not quantity . I'm telling ya peeps when a UVB source increases the amount of trichomes on your bud it may very well be that your primary source was lacking to begin with or at least that's what I saw in my limited experience trying to use UVB. And just because someone posses a great cut doesn't guarantee a great crop every time, right? Especially when a grower deviates from what they usually do, like changing your mix recipe or nutes or say like having been growing for years with CFLs and then less than a year with LEDs. Perhaps something like that????

Also, IMHO, when you run your COBs too easy, and I'm not saying that's the case with the OP, but when you run soft the extra spectra created isn't as prevalent, intense or as energetic as what the manufacturer is showing us. There are other factors, like blend/phosphors used by the manufacturer, that will alter the light sources output too as I'm sure you cobsters probably see when you run your SPD numbers. I like efficiency like everyone but sometimes too soft is....too soft in my book and any additional extended spectra may not be working in your favor as well as it should.

I've always doubted COBs as far as a complete cannabis grow spectrum go, and there may be some truth to what the OP is saying so to finish, besides the fact that I can go back and pull up a photo or two of bud grown with just LEDs that will put to doubt any of that "LEDs don't grow frost" stuff, some strains that I've previously grown don't seem to be as frosty as to what came out of my tent with the Chinese diodes I previously used but that the overall product is much better now with the addition of COBs replacing inefficient mono wattage + CREE bulbs. That's the paradox I see and I do wonder if that it is related to spectrum, excessive blue in the flowering area now with all the COBs or simply the limits of my environment and my growing skills atm?

superbak3d said:

That's why you just add CFLs or a reptile bulb.

I'd highly recommend anyone using LEDs to supplement with CFL or floros. You don't need much, just a little extra UV can go a long way.

The resin is what protects the plant from natural UV emitted by the sun. So obviously the higher the UV amounts the more resin production.

There's a limit though, too much UV and all that resin can burn up and your whole crop will be wasted.

Think of it like how human skin reacts to sun. High levels of UV makes us tan, but too much and burrrrrrrrn. There's also the opposite, where we can be outside in the sun all day with low UV and never burn or tan (spring/fall sun). This is where I place LED. You can be in it all day and you're not going to get burnt, or even tan.

That's why LEDs lack in the frost department. They obviously still produce resin to protect themselves from light burn, but not as much when UV is present.

So the solution is simple, just add in cfls on the sides or some floros. They'll give your buds a nice little boost in the frostiness.

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A sun tan is a good analogy. They're not gonna get a tan under LEDs, but the light is intense so they will put out a lot of resin to protect itself from the phototoxicity. However, UV causes a reaction where something else turns into THC. I don't remember what, maybe just THCA. Point being, there is a reaction within the resin glands involving UV but you don't want too much either or the THC itself will degrade. That's where the nice little CFLs come in, hopefully.

Has anyone tried CFL blacklights?

BobCajun said:

Has anyone tried CFL blacklights?

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Your best source for a UV supplement is to use the reptile bulbs. available in T5HOs. as an additional benefit they also include light in the actinic ranges.

I've used Zoomed T5 HO Reptisun 10.0 UVB bulbs.

Arcadia D3+ 12% UVB t5ho reptile bulb,Ive used this.

As far,as turning THCA into THC in the trichomes,I dont see the use.This happens during decarboxylation anyway.Since moving to cobs ive noticed a big difference in bud mass over T5HO.My suspicion is the much higher intensity is degrading thc some,but offset with higher yeild.Just my thoughts on it.