my bad chainer!
and AE, according to a lot of threads at cannabis culture by people who have been posting there for a long time and have many grows under their belt, LED can grow some killer bud. Have you used LED personally or seen a grow that uses them? I haven't, I'm just going off what I've seen over there and my experience with HID.
As for the inverse square law, LED widens the footprint while bringing the plant closer to the light source. With one source of super bright, hot light, you have to have the plants further away. With many sources of cooler light, still amounting to the same wattage, you can have the plants closer and still have the same foot print. There is also the factor of utilizing only the red and blue spectrums with a some white supplementation. And also the fact that LEDs are more efficient users of energy per photon emitted.
Maybe there is something I'm missing, but it seems to me that LEDs are the future of indoor growing.
Hiya mate, sorry but with respect, I don't agree with that. This is what you get when you go to forums such as Cannabis Culture and Rollitup which are poorly moderated. You'll find that very few people even know what potting up in soil is on those forums.
To save time, I'll cut and paste what I wrote in old archived thread to save time:
Sorry that's wrong. LEDs are a complete joke and time and time again they pale in comparison to HPS. They're for the High Times readers who have more money to piss away than sense. Fair enough, if you want a pretty set of lights in your grow room for bragging rights, they're okay, but for real growing, they're inadequate. I've noticed a lot of people claiming how effective LED lights are in certain american forums (not that I have anything against americans lol) but on the main british forum used by thousands and thousands of users, there has never ever been even one successful grow. The only person who stuck through the whole grow using LEDs said they were shit and ended up going back to HIDs in the end anyway!
This isn't aimed at you, but it always surprises me what people will believe on Youtube! Just because some manufacturer has done a grow (or hired someone to/given them free stuff to)use/using HIDs and then switched the light to LEDs at the end to make it look like the whole thing was successfully done under LEDs doesn't make them effective. AFAIK even CFLs do a better job than LEDs!
If they were to produce an LED that was a about 5cm in length and gave off as much useful light as a measly 250 watt HPS and as efficiently it really would be an achievement. It still wouldn't be worth buying though as it would be incredibly expensive. LEDs do NOT give off less heat than HID lights, this is myth that I hear time and time again. Heat isn't such a bad thing with HPS lights anyway like people would believe, since moving the plants further away gives a much larger footprint (inverse square law) which they need anyway and penetrates the leaves etc much more, giving better growth, especially with cannabis plants much taller than the lettuce LED grow lights was designed to grow. Diffused sources of light such as from LEDs up close to the plants are blocked by the first set of leaves it hits.
If it were me, I would stick with a tried and tested technology (HIDs) that's been around for 50 odd years and has been developed constantly in this time, instead of a new gimmick (LED grow lights, not the LED itself) designed to suck your money from you.
Don't be a sucker. I could probably do a better grow than with the latest fancy LED grow light on the market just by using half a dozen 10p CFLs from the local supermarket!
Sorry if this offends anyone but I'd rather just say it than pussy foot around the issue. It's better if I just say it how it is.
Unfortunately this issue with those forums has been recognised by people that are really very experienced with growing weed who have issue with the blatent bad respect and have migrated to a couple of other forums where they don't stand for disinformation being disseminated.
There are a lot of LED manufacturers cashing in on the naivety of growers with no experience and because there is a freeforall, a lot of them are posing as growers posting fraudulent positive experiences with them.
I'm only telling you this because I don't want you to waste your time or money mate, not to give you a lecture. There's only been one completed LED grow on the more respected forums that anyone's aware of and the guy got quite despondant at the end because of how disappointed he was and said he'd vow never to use LEDs again! I really don't want to have to say I told you so. You'll find that absolutely none of the commercial growers that have had any succcess go for LEDs, so that suggests something in and of itself.
As for the inverse square law, LED widens the footprint while bringing the plant closer to the light source. With one source of super bright, hot light, you have to have the plants further away. With many sources of cooler light, still amounting to the same wattage, you can have the plants closer and still have the same foot print. There is also the factor of utilizing only the red and blue spectrums with a some white supplementation. And also the fact that LEDs are more efficient users of energy per photon emitted.
What I meant is with the inverse square law there's the same number of lumens close up as there is further away, over a larger area. So, if you bring the plant closer, whilst you'll get a higher light intensity you'll be covering a smaller area. I just found your comment a bit confusing is all:
-The plant can grow very close to the light, even touching it. This maximizes the inverse square law of photons.
Perhaps at some point in the future LED technology may work, but I have my doubts and there is no model that comes anwhere close to an HID and there won't be for a long time.
Oh and you wouldn't be able to build an LED array yourself since it's not as simple as hooking up a whole load of LEDs in a matrix. The electronics would be more complex than that.
My uncle who is quite a high flyer that works for a company who is involved in r&d at an LED manufacturer seems to think they're quite a way off anything remotely useful for growing weed and has his doubts that it will ever happen, since there are other better technologies in the pipeline at Phillips et al. LED grow lights were developed by NASA for growing lettuce on spaceflights and as such were never intended for cannabis. They just don't have the ability to penetrate the foliage meaning that only the very top will get significant exposure to light. Why anyone would want to spend thousands on a technology that doesn't work for growing weed when you have tried and trusted HID lights that have been around for decades is beyond me. Perhaps you should maybe contact the commercial growers in California (if you can) to see what I mean if you don't believe me?
Sorry if I sound like I'm being condescending, that's not my intention. I just hate people being given crap advice by people who are ignorant or have a hidden agenda.
If you're lucky that £200 panel might be about as good as 6 20w bulbs for 60p from tescos. With growlights you have the added element that since the application is illegal in most parts of the world, bar the likes of California and there's no money back guarantee when they turn out to be crap so this is why the business is highly profitable.
There are some 200 lumen per watt LED's on the horizon but light penetration is so piss poor they will still have to be treated like cfl's.
LED's are only suitable for scrogs and do not work for big plant growers.
Worst lie with LED's is they don't produce heat.
I can grow plants under HPS and swap them for LED's when I take pictures if I was a manufacturer and that is why all LED pics I've seen with good results are faked because the temptation is too great.
edit: by the way, I've heard numerous reports of people on these american forums actually getting their posts deleted when they talk about
why the LEDs have poor penetration etc. That is highly suspicious to me, since it's quite possible that they get payments from the LED manufacturers.