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LED vs HPS by Shitting Blasslefoot - Thu, 12 Jan 2017 08:40:50 EST ID:aA2vxYkU No.143880 Ignore Report Quick Reply
File: 1484228450404.jpg -(4664780B / 4.45MB, 5312x2988) Thumbnail displayed, click image for full size. 4664780
so ive been told you can get as good results with leds as you can with hps im skeptical but id love to be proven wrong can anybody confirm or deny this
>>
Caroline Clegglemat - Thu, 12 Jan 2017 12:27:23 EST ID:nHSIskyy No.143881 Ignore Report Quick Reply
>>143880
You need very powerful, very expensive LEDs, and you need a lot of them, and they need to be in the correct light frequency. If you can do all that though, yes, they are better than HPS, if you have fine control over light frequency (wavelength) you can even stimulate the plant to make an unnatural amount of trichomes.
I have a magazine article saved on my other laptop but can't be assed to get it right now. Don't worry, I'll post it, I've posted it before. Check back in a day.
>>
Nicholas Pittlock - Thu, 12 Jan 2017 13:23:07 EST ID:Ifg1Jte4 No.143882 Ignore Report Quick Reply
>>143881
awesome thanks man
>>
Priscilla Fackleman - Fri, 13 Jan 2017 13:44:47 EST ID:lE51QiPd No.143889 Ignore Report Quick Reply
>>143880
You can. Again, you do need good LEDs, but the price is coming down fast and the quality is rising just as fast.
LEDs are excellent for low power and heat consumption. A 600W LED will save you a fortune compared to a 1,000W HPS (which is more like 1,200W if you use a magnetic ballast.) It will also reduce heat by a fuck ton. Which can be an issue.

Honestly, I think most people grow in such a way that the difference is minimal. Most people aren't skilled enough to get those monster grows where you get a fucking pound per plant or some shit. Focus more on getting your nutes, and you will probably be able to get equal yield from the two.
>>
Archie Turveywater - Fri, 13 Jan 2017 20:45:16 EST ID:nHSIskyy No.143891 Ignore Report Quick Reply
1484358316313.jpg -(1823634B / 1.74MB, 2550x3300) Thumbnail displayed, click image for full size.
>>143882
Hey man, here you go.
>>
Archie Turveywater - Fri, 13 Jan 2017 20:46:06 EST ID:nHSIskyy No.143892 Ignore Report Quick Reply
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page 2
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Jarvis Wummleham - Sat, 14 Jan 2017 02:13:57 EST ID:Ty1RNEku No.143895 Ignore Report Quick Reply
>>143891
what a stupid fucking article, those plants aren't white because of unnatural amount of trichomes, they're just bleached by a huge amount bad quality light. It's common even with low wattage LEDs. The bleaching isn't a good thing.
>>
Sidney Povingbanks - Sat, 14 Jan 2017 04:11:52 EST ID:lOcEBwwf No.143896 Ignore Report Quick Reply
>>143880
LEDs are better than HPS
prove me wrong
>>
Shitting Drablingwidging - Sun, 15 Jan 2017 07:02:28 EST ID:uUmmRaTA No.143904 Ignore Report Quick Reply
>>143891 thanks bro legend fuck i love this site, can you recommend any particular lights? and do you know if there are any other important factors other than the 660 nm red and the absence of 680nm red
>>
Shitting Drablingwidging - Sun, 15 Jan 2017 07:04:54 EST ID:uUmmRaTA No.143905 Ignore Report Quick Reply
do you need a different amount of lumins too when you're growing with hps ?
>>
Wesley Duckford - Mon, 16 Jan 2017 08:36:45 EST ID:PX/ZPh4W No.143908 Ignore Report Quick Reply
>>143895
nah mate, mold.
>>
Wesley Sazzletun - Tue, 17 Jan 2017 15:46:46 EST ID:+feR4wOL No.143918 Ignore Report Quick Reply
>>143895
That's what you get when you get re-sellers of Chinese crap-o-matic growlights get to sponsor a "journalist".

I'm far from saying that LEDs aren't useful, but you have to know that a vast majority of lights sold are still complete crap.
Plants grow under them and subjectively you get decent results, but these tests rarely provide weight measurements of the trimmed, cured and dried buds along with the at-the-wall power consumption of the lights used.

Unless it's larger than 1 gram per watt it isn't even worth looking at because that is the benchmark for any HPS above 400W.
I haven't seen a single test of any LED grow light that is marketed in this fashion and the excuses range from claims of more trichomes, more THC or better taste for which zero evidence is being presented.

LED lights that do actually outperform HPS fixtures are either some DIY project somebody has done or quite hard to find stuff built by enthusiasts that made it to the next level.
In theory there is a third class of LED lights that are worth it and that are products built for professional agriculture, sadly these are hard to come by.
>>
Wesley Cummerdale - Wed, 18 Jan 2017 20:26:22 EST ID:D9sRlYVv No.143921 Ignore Report Quick Reply
>>143918
why are the professional lights hard to come by are they just expensive or are they not generally available to the public?
>>
INTERPOL !3mB4iDBpWw - Wed, 18 Jan 2017 21:14:17 EST ID:w/eMcEZe No.143923 Ignore Report Quick Reply
>>143904

With the near IR and IR up to 730nm you can introduce the Emerson effect that gives you a full 12 hours more per week of daytime for the plants to use. 730 IR's are what is used to make Chlorophyll F which was recently discovered, the jury is still out whether or not it's necessary to have or useful at all. I've had a lot of luck with Cree's full spectrum COBs that hit every range just about to give you some of the most natural looking light I've seen come from an LED yet. Between 60 and 70 degrees are the best angles I've used in collimators, they put a nice spotlight right where I need it at a reasonable height. The only time I've ever had a problem with bleaching is when you have an LED or HPS that's putting out more lumens than the sun does, I've had a quarter million lumens coming off of an HPS at 4 inches before and it bleached the very tips of the top of the plant.

>>143921

It's the same with anything else, you get what you pay for. If you want to build your own LED array and can do the math with forward voltages, use a meanwell power supply or something equally as good, and use the knowledge of PC builders when it comes to cooling it and using a quality thermal paste instead of the mayonnaise they splatter onto theirs, you can build something from scratch that doesn't look pretty but blows the Chinese arrays out of the water when it comes to quality of the build.

>>143905

You're going to want to measure in PAR instead of lumens with LEDs, it's not the amount of intensity so much as the usable spectrum being absorbed compared to HPS, because you will be tweaking the spectrum if it hasn't already been dialed in by the manufacturer. A lot of the Chinese builders are more than happy to build something to order for you, if you don't like their spectrum, tell them what you do want and the amount of it that you want, and they'll work with you.
>>
Cornelius Bricklekeg - Thu, 19 Jan 2017 03:35:21 EST ID:+feR4wOL No.143927 Ignore Report Quick Reply
In regards to DIY, holy moley, check out digikey....

Samsung just got into building COBs and fuck they blew it out of the water!
these parts...
SI-B8V05128HUS
SI-B8V11156HUS
SI-B8V221B2HUS

179 lumen/watt for 3000K strips, measured at 50 deg Celsius, priced at ~1 Euro per Watt
>>
Hamilton Clambledock - Thu, 19 Jan 2017 12:27:14 EST ID:xthRZCcw No.143928 Ignore Report Quick Reply
>>143927
should be easier to cool then cobs
Is there a thread somewhere about these ?
>>
Emma Sandlehall - Thu, 19 Jan 2017 14:19:53 EST ID:lE51QiPd No.143929 Ignore Report Quick Reply
>>143927
I'm not sure on those. The actual spectrum of "warm white," bulbs is keyed to what we can see, not what plants need. Plants, for example, pretty much ignore green light. So any energy put into producing that part of the spectrum is wasted on plants. It is great for people, because we actually see green better than anything else on the spectrum. Plants don't care though.

The best lighting system will be the one that has the most efficient conversion of energy to usable light for the plants. That is the key. How many watts of power can be converted into usable photons.
>>
Cornelius Bricklekeg - Thu, 19 Jan 2017 18:47:54 EST ID:+feR4wOL No.143930 Ignore Report Quick Reply
>>143928
Yeah cooling these should be just the matter of mounting them on extruded aluminum u-profiles, no need for expensive heatsinks. But then they are still a bit more expensive than the compact variants, but then those aren't as efficient.
It should also enable you to spread light over a wider area or mount them on the walls, etc..

>>143929
That is, to my knowledge not an issue. While plants do not use green light as efficiently as red light it is nowhere near wasted. Of course people trying to sell you LED panels built with the traditional red/blue combo will tell you something different.
But then there are plenty of people having great successes with growing under white just LED COBs, often surpassing the 1gram/watt barrier significantly.
There is also a theoretical basis for this in case you are interested, this has been known since the 70s btw. Starting point is the McCree Spectrum (google it).
There is loads of research regarding this if you want to dive into it, in the end it comes down to that plants generally have other chemicals in their leaves besides chlorophyll contributing to photosynthesis.
For what it's worth the spectrum of a warm white LED matches the McCree spectrum almost perfectly, although it could be very slightly improved with a little extra deep red. But then if the light is already this good you could call it a very decent compromise.
>>
Augustus Bomblelire - Thu, 19 Jan 2017 19:21:43 EST ID:+feR4wOL No.143931 Ignore Report Quick Reply
1484871703829.png -(221185B / 216.00KB, 800x344) Thumbnail displayed, click image for full size.
>>143928
These are probably so new that nobody has gotten around to using them yet.

>>143929
In case you're wondering *how good* the 3000K LED spectrum matches I found a chart. There ought to be slight differences depending on the manufacturer but you get the general idea...
>>
INTERPOL !3mB4iDBpWw - Fri, 20 Jan 2017 01:25:24 EST ID:w/eMcEZe No.143937 Ignore Report Quick Reply
>>143931

I can't bring myself to agree totally with this graph, UVB in the 375-395nm range will help the plant to produce more resins as a defense mechanism against getting sunburned. This has been shown by using UVB reptile lights in bloom, and they spike in the blue range instead of the red which otherwise shouldn't help at all in bloom.
>>
INTERPOL !3mB4iDBpWw - Fri, 20 Jan 2017 01:31:09 EST ID:w/eMcEZe No.143938 Ignore Report Quick Reply
>>143928

COBs are easy to cool because all you have to do is use thermal glue to attach them to just about any size CPU heat sink, then affix the proper 90mm fan that goes onto that cooler. The sky is the limit, you can even water cool them if you want to push a 100-150W rated COB to 175-200W. Otherwise heat buildup is what kills them quickest.
>>
Augustus Bomblelire - Fri, 20 Jan 2017 04:12:19 EST ID:+feR4wOL No.143939 Ignore Report Quick Reply
>>143937
Isn't UVB shorter wavelengths than 375-395nm? That is UVA to my knowledge. And AFIK no other light besides specialized florescent bulbs provide it, so if you want the benefit you'd have to supplement it either way.
>>
INTERPOL !3mB4iDBpWw - Fri, 20 Jan 2017 07:27:04 EST ID:w/eMcEZe No.143940 Ignore Report Quick Reply
>>143939

275-320, you're right. They claim to make LEDs that can reach that wavelength but they're around 10x as expensive and last I checked they were a lot weaker in intensity.
>>
Fuck Movingworth - Fri, 20 Jan 2017 11:47:04 EST ID:lE51QiPd No.143943 Ignore Report Quick Reply
>>143940
LEDs have always had trouble producing UV light.


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