Experiaments with gen 3 LED's lights

[mace]

I have no doubt that they aren't there yet but i was hoping with 4 to counter the weight issue using added intensity.

It was really the fact that i could be looking at 2lbs+ if i just use these as side lighting that got me thinking, lol. The coffers are on the low side after this recent purchase, and i could use some chronic bubble gum.

 

[mace]

Well, the temp is 85ºF, i have a 650 cfm fan attached and it's got three passive 4 inch holes in the tent, plus some mesh holes. The fan is run through a few 45 degree sharp angles so im sure im losing volume. Dunno how to get the temps down more, 85 might just have to be good.

Also, i dunno about the vertical height with all that reflector in the way.

 

[British_Hempire]

They might have a small benefit as side lighting, but I can't see them having much use on their own, all four together gives you about the same number of photons as you would get from a 250W HPS. A 250W HPS outputs almost 250uE of photons, the people who sell the UFO don't state the output of the UFO, but it will be 50-75uE at most, so you are gonna need 3 of them to come close to matching a 250. The low output is supposed to be compensated for somewhat by having a more correct spectrum than a HPS or fluoro,, but the UFO has a poorly designed spectrum.

I'm not sure what to suggest a the best way to get some benefit from the UFO. The design with all the LEDs clustered together is a bad one, gives very poor light distribution, so to get a decent spread of light you have to place them a fair distance away which means low intensity light hitting the plants as with LEDs you need to keep them close to the plants as the intensity falls off fast with distance. Probably the best thing to do is put one in each corner of your tent and hope it gives you some benefit in fattening up the lower buds.

Sorry to be negative but the UFO really is a poorly designed over-priced piece of kit, you can say the same about all the other LED lights on the market. The Procyon and Lightblaze have some potential, but still suffer from the same issues - all the LEDs bunched together (moderated somewhat by the inclusion of a curved plastic panel that spread the light a little) and a low output. The manufacturers have to make such wild unsubstantiated claims as 'equivalent to a 400W HPS' to justify the huge prices they are charging, I mean, no-on would pay hundreds or thousands of dollars on their LED lights if they told th truth about how much light they are actually outputting.

 

[mace]

BH: im starting to agree more and more with you, but i dunno if you had noticed i slapped a 1k HPS in there.

 

[Zoolander]

I still say the UFO's are great for veg

 

[British_Hempire]

What I meant was stick one UFO in each corner as a supplement to the 1k, the added red spectrum could have a very useful impact, I want to try using red LED lght to supplement a HPS myself, just not got round to it yet.

They do work for veg as vegging plants don't need much light, I have great success vegging under just 25W of blue LEDs.

 

[mace]

Yes, i will definitely say for veg they work beautifully.

This isn't an update so much as it is to mark in the thread when i turned the plants. 2-5-09 @ 7pm was their first day in 12-12.

 

[Paolo]

Hi Guys,
Enjoying all the experimentation with LEDs.... it's good to see.
I know you've all probably seen www.greenpinelane.com , but there were some good tests there.... anything that can grow tomatoes is promising....

I built myself a ~240 watt array a while back using two 104 watt 627nm Lamina panels (used as runway lights on airstrips - hell bright), and luxeon royal blues and cool whites. I had some *amazing* veg results with them - at least equal to a 600 watt mh.....but flowering was a lot slower.

Myself I think adding a small hps to an led grow at flower would work really really well. You keep the benefits of low energy consumption and reduced heat sig, and the added spectrum of the hps would really kick off flowering.

I think you should keep experimenting with the LEDs, and don't worry about people jumping on you telling you they won't work... despite the fact they aren't producing the leg-sized buds of hps, they also aren't producing massive amounts of heat or drawing huge amounts of power.

what's the three ufos using? less than 300 watts? how's the heat signature? None? I'd call that a win even if the buds aren't huge. Where stealth and low power consumption is an issue I still think LED is the go.

 

[mrnicegrower]

nice grow m8, nice lookin plants, but gotta agree with most comments, in my eyes u cnt beat the traditional way of bringin your young 1ns up, the results alone should tell u that, so wot if it costs? u cant beat the buzz at harvest time when u r draggin your trees like dead bodies lol, n wiv your method i just dnt think u will get that body draggin factor, i mean cum on guys we all doin this for big stinkin buds man, thats where the luv is

 

[Texas Kid]

I have seen alot of side by sides of vegetables and such, those look promising, but I think there is a huge difference in those and a flowering plant, especially one that the flower cycle is phototropically induced. Also the peformance of the plant is in direct relationship to the amount and concentration of light it is getting, not many plants like that so it is hard to do a comparrison.

Tex

 

[British_Hempire]

Well, the thing is that each plant species has a different photosynthetic response curve and no-one has yet worked out what the correct one is for cannabis, I expect within 2 years knna and his team of spanish experimenters will have this ironed out. Also, we need to start matching the uE per m2 of HPS with LEDs, which means better efficiency LEDs and currently large expense, but LEDs will keep getting cheaper. It;s early days and right now we need to do a lot of experimenting before we have all the answers.

 

[Paolo]

Yeah, I think the operative word here is experiment....

There is nothing to be gained by shooting people down who are experimenting. You're actually just shooting yourself in the foot, coz they are doing the groundwork for the next technological advance...

The results I had with my homemade LEDs were very promising. Considering there was no heat - the lights were cool to the touch - it was a total success from a stealth point of view.

As has been stated numerous times, the 627nm / 455nm red/blue combo is not enough - you need 660nm far red, some infrared, green, and UVB as well. Once the price on 660nm diodes comes down I think we'll start seeing some HPS killing tech happening, but price is still prohibitive. As cities start to change street lights over to LED there will be some profound changes to the industry, too.

Until that time I think the sweet spot is in LED+HPS. I'm looking forward to trying a 240w LED + 90w HPS micro grow. I'll be interested to see the effect that has come flower time.

 

[mace]

Good to see further discussion going on in here. British, i didn't know you had run into knna, i used to be on gardenscure frequently and that's where i started learning about led's. Small internet.

Small update. day 4 of flower, the first signs are showing at the nodes. I know im going to need to do some vertical trickery to get this all to fit in here so i decided to LST the plants. Pictures are below.
I was able to lower the light 12" 's by doing this and it will only help the yield. I plan to get new light hangers for repositioning the LED's to the top corners.

LST'ed in the back, not in the front

 

[British_Hempire]

Yeah, I think the operative word here is experiment....

There is nothing to be gained by shooting people down who are experimenting. You're actually just shooting yourself in the foot, coz they are doing the groundwork for the next technological advance...

The results I had with my homemade LEDs were very promising. Considering there was no heat - the lights were cool to the touch - it was a total success from a stealth point of view.

As has been stated numerous times, the 627nm / 455nm red/blue combo is not enough - you need 660nm far red, some infrared, green, and UVB as well. Once the price on 660nm diodes comes down I think we'll start seeing some HPS killing tech happening, but price is still prohibitive. As cities start to change street lights over to LED there will be some profound changes to the industry, too.

Until that time I think the sweet spot is in LED+HPS. I'm looking forward to trying a 240w LED + 90w HPS micro grow. I'll be interested to see the effect that has come flower time.

I hope you're not inferring I'm trying to 'shoot people down' as I'm experimenting with LEDs myself.

660nm LEDs are crap, they use an older less efficient material than the more common 625-640m red LEDs. Also, the difference in plant response between 640 and 660nm is so small, it is far better to go for a 625-640nm LED that is more efficient, knna has detailed all this before. Also, the thermal issue has to be bore in mind, the 625nm dominant wavelength quoted for a red LED is at 25C, but rises with temperature, so if your 625nm red LED is operating at 60C, it's spectral output shifts upwards, making it have a dominant peak of say, 640nm and some output all the way up beyond 660nm.

As for needing infrared, green and UVB, where is your evidence for this? Any scientific research to back that claim up? UVB LEDs are extraordinarily expensive, hundreds of dollars, specialist items from companies like Marubeni and Roithner. No-one has ever been able to show ANY link between UV light and flowering cannabis, and some serious fellas with PhDs have studied the topic and come up with nada. Also, all the fluoroescent and discharge lights we have been using to grow with for the last 30 years have ZERO UV output, they are designed that way by law - they have glass envelopes with filter out any UV, so if UV was important to flowering cannabis then folks wouldn't have been getting such good results with fluoro and discharge lighting all this time.

I don't know where ya got the idea about green from, got any references to back up that claim?

Read this post by knna, it is one of the best on the subject I have seen:

625nm dominant wl red LEDs are usually about 632nm peak. And take in mind than that figure is given at Tj=25ºC (Tj=temperature on the junction's chip). LEDs vary spectrum as the chip heats. Red AlInGaP LEDs (most efficients currently) increase its peak wavelenght at about 0.14nm/ºC (if depends of the model, but it is give or take, aprox correct for most). It mean the a 625nm dominant wl LED have a peak wl on operating conditions (60<Tj>80ºC) between 635 and 640nm. Thus, 625nm dominant red LEDs are in fact 640nm LEDs.

Most manufacturers has the longer red bin of 625-630nm (dominant) aprox, which correspond, on operating conditions, to 635-645nm (up to 650nm if running hard).

Im going to get some Edixeon for testing this month. If i think they work fine, and there is demand, i could sell them (BTW, way cheaper than price quoted at LED tech, about 35% less). As i get large batchs of LEDs and components (drivers, heatsinks, etc) im thinking on selling kits for hobbyist wanting to do their own LED lamps. Im already doing it locally, it would be just shipping worldwide.

I want to perform some experiments with the far red edixeons (740nm) to determine its usefulness for growing and what amounts are required.

If you tell me what bins are the Red XR-C and the K2 WW, i could be more accurate. But roughly, it is going to emit about 150uE (on PAR, UV excluded), meaning an average light density of more than 400 uE/m2, that promises a good yield. RGB (B=400-500nm, G=500-600, R=600-700nm, simplified ranges) distribution about 65-20-15% which i believe is a very good one.

With the amount of far red added by the whites (specially the WW), i believe you are done. Although at some special stages, mainly flowering induction, an higher amount of far red should shorten the time needed to reach true flowering (but its as simple as adding an incandescent bulb during the first week after flipping photoperiod at the end of the light period, for 1/2h). I think that having an far red LED's spot for this purpose, aswell as controling phenotype expression would be very useful, but not strictly required.

I believe terpene's production enhancement is related to short blue, violet and UVA, although i think its effects are modulated by the amount of other colors (i suspect yellow and amber).

 

[mace]

i just wanted to piss and moan a bit. The seedlings i started not long ago are having a really rough go at things. I planted them straight into black gold soil 60% pearlite 40% and they breached 3 and 4 days later. They've had one feeding of bio-tea and full earth juice line-up @ seedling rates. They've also had gonats dumped into their soil to kill of the infestation i've had flying around for a bit. (think i finally got all the fuckers)

Yesterday was their second time getting tea, it's brought 3 back from the brink and i dunno about the other 2 im worried about. I put a humidty dome back on top of them for added support and tonight im planning on flushing with RO water, and re-nuting them back to seedling levels. The lockout that i think im seeing maybe coming from the go-nats. I'm really unsure and am just going with what i know works for other lockout issues. Any insight is much appreciated on this topic. I also happen to have some loaded soil hanging around. It's a bio-flowering soil but i wonder if mixing it 50/50 with the blackgold would work well to plant these guys straight into. Could deal with all my problems at once.

 

[ismokepot]

From experince, you'll never get a lb. from your 4 plants under these lights......... but that's just my opinion. Maybe 8-10 oz. if your lucky. Good luck and keep us posted.

 

[mace]

From experince, you'll never get a lb. from your 4 plants under these lights......... but that's just my opinion. Maybe 8-10 oz. if your lucky. Good luck and keep us posted.

IT's only 2 plants.

turned at 30" and now LST'ed. Im shooting for two half pounders' and with the light intensity i have, i doubt these plants wont give me half lb a piece. Might be dreaming, but i like to aim high.

 

[Paolo]

I wasn't speaking to you British Hempire..... and I didn't realize this was a pissing contest..... 'serious fellas with phDs,' indeed...pfft. jeezus mate, take a powder.

I'm speaking from the experience I had with home made high power LED arrays.... observation of the plant's progress..... just little things like that.

Seeing as one of the chlorophyll peaks is dead on 660nm you'll have to forgive me for thinking that 660nm LEDs are a good idea. I guess I'll just stick with the ones I've got. The green I refer to is the visible part of the spectrum that was initially ignored by the red/blue system as the plant reflects *most* of it. I believe that some of this part of the spectrum *is* actually needed. I read that the cannabis plant produces more resin glands as a reaction to UVB. I don't have the references at hand, but I'll have them on your desk by Monday, sir.

oh and compact fluoros give off uv..... so don't sit under them for too long.

 

[mace]

Update time, 25 days into flower. The yellowing are the leaves that are lost due to a heat burn. First time growing with a 1k in this tent, lol. I'm thinking these things are going to end up packing on the weight.

Light burn after, 2 weeks post burn

And im smoking this green crack, taste like candy

 

[British_Hempire]

I wasn't speaking to you British Hempire..... and I didn't realize this was a pissing contest..... 'serious fellas with phDs,' indeed...pfft. jeezus mate, take a powder.

I'm speaking from the experience I had with home made high power LED arrays.... observation of the plant's progress..... just little things like that.

Seeing as one of the chlorophyll peaks is dead on 660nm you'll have to forgive me for thinking that 660nm LEDs are a good idea. I guess I'll just stick with the ones I've got. The green I refer to is the visible part of the spectrum that was initially ignored by the red/blue system as the plant reflects *most* of it. I believe that some of this part of the spectrum *is* actually needed. I read that the cannabis plant produces more resin glands as a reaction to UVB. I don't have the references at hand, but I'll have them on your desk by Monday, sir.

oh and compact fluoros give off uv..... so don't sit under them for too long.

Where did you read that cannabis produces more resin glands as a reaction to UVB? Was it in a proper scientific paper or a pseudo-scientific article on the net?

Compact Fluoros don't give off UV, neither do tube fluoros - billions of people sit under them every day with no adverse effects, there may be a tiny teeny amount of the high UVA/near-UV band (380-410nm) but there is very definitely no UV of lower wavelengths. This is something enshrined in laws around the world, and also goes against how fluoros work. A fluoro produces a large amount of UV light internally, but the phosphor coating absorbs this UV and then produces visible light. The entire surface area is coated with phosphorous. Tanning tubes don't have this phosphor coating so they do emit UV.

Green LEDs are a bad idea, use white ones instead as they have sufficient output in the green/yellow part of the spectrum to cover any green absorption that MAY take place, but seeing as folks in the horticulture industry regularly use green lights as safe lights to allow them to see during the lights out period without disturbing the plants, I really doubt there is any reaction to green light.

660nm LEDs are only available from a handful of manufacturers, Norlux make a high power array that is very expensive but their online shop hasn't worked for a year and they don't answer emails. LEDengin make 5, 10 and 15w deep red LEDs but they are a pretty poor product for the price they charge - they claim 5W but the V drop of those LEDs is rarely higher than 2.5, making them a 2.5W device, and they are mounted on crappy thin stars with bad solder pads, try getting a good solder joint on them, they are crap. Edison do a 1W 350mA deep red, not tried them out, but they are based on old technology and the substrate chemistry is a couple of gens back from the current state of the art and therefore nowhere near as efficient as other red LEDs based on more modern technology. The new Edixeon Federal 660nm could be interesting though, it has the same footprint and packaging as a Luxeon Rebel so can be mounted on triple stars, but it still uses the same old inefficient die as the earlier deep red Edixeons.

knna has written some very well researched and detailed posts about red LEDs and the poor efficiency of 660nm parts currently available, in fact, anyone wanting to know all about LEDs and their use in powering photosynthesis should read all of knna's posts on the subject as he really does have all bases covered in his work.

This isn't a pissing contest, this is all about sharing knowledge, but it must be CORRECT knowledge and that usually requires a basis in scientific fact, I know it takes time to do the research to back up the theories and real-life observations, but it is highly worthwhile to do so as without the supporting research, theories are worthless and observations hollow of significance.