DiY LED - Cree CXA3070

[SupraSPL]

I have tested them on 240V and they worked just the same I think @Greengenes707 runs his on 240V.

 

[Castaman]

Does it make any sense to use a reflector with cobs?

 

[SupraSPL]

Yes it can be useful if you need to increase vertical height. See @Positivity setup

 

[Greengenes707]

I really think reflectors are great. I have done small test with gloss white poster board and it can increase your par readings by 25% on the outer edges sometimes.

And yes the ebay drivers will run automatically on the stated wattage. I have run them on 240v and have one 120 as well...never skips a beat. And at 240v with their load basically full...will have the greatest efficacy potential too(based on general electronics behavior...I have no data sheet for it).

 

[Chigur]

Thanks for the replies, not sure i deserve them after saying 110/220v !! "Greatest Efficiency potential"...I like the sound of that.

Its like this, i havent much electrical skill but i have a bucket of confidence in my ability and with you lot on my side even more so. The plan is to build a few bars once i gain the necessary skills, ill start out with a few single COB units, learn and move on to more complex things like a bar. Ideally the bars are dimable but a few questions remain after reading this entire thread over he last few days. Ill be going a bit bigger than most of your grow, prob 2500- 3000w.

Questions:

Lenses...Id like to ad to the bars some 730nm for flower initiation, intensity doesn't seem and issue for the 10 minutes the plants need to be stimulated, I see the commercial flood light available. if 10 w can cover 8sq feet then i guess i wont need much. Is there a way to put say 1 x 730 LED on a 1 meter bar with lenses to get better coverage?

What would be the ideal spacing of the 3070ABs(in the post) on a 1 meter bar?

Suggestion on my learning curve and build? I plan on using as clips in thing to keep my soldering and exposed wiring to a minimum.

...Do any of you supplement with Co2.

Thanks

 

[SupraSPL]

Wow thats a big build amigo! You can get a lot of infrared from every day halogen lights and since they are only on for 5 minutes the heat and electrical use should be negligible.

Also with a build that size CXA3070 AB bin availability may be a problem (the last of the 100 pack on Arrow just sold out). The Vero line has recently updated spec sheets showing improved efficiency and thermal performance. Combine that with the price drop at Digikey and the Vero is looking good, great news for DIYers that like to run hard. I have been working on updating my data sheets for the all the Veros. Here are the "typical" numbers for the Vero29. The CXA still outperforms in cost and efficiency at low currents 350-1050mA but they are near evenly matched at mid current 1.4A and the Vero performs slightly better at high currents. (CXA3590 a better comparison at high dissipation)

 

[Chigur]

Great info, i helped sell that 100 out, i have 20 x CXA AB's on the way and a request in for 40 more, not in a huge rush but ill keep the Vero's in mind. Waiting on 6" heatsink bars to come available.

Do you have more info on the Halogens as flower initiators?

Thoughts on bars vs panels?

Sorry but after all this reading im still wondering, with the intensity vs efficiency what is the sweet spot as far as GPW? I know some crank it up to make the buds more dense or what ever, Im not concerned with that nor on the other side driving the units too hard, im a total yield whore. Ill be doing one or two strains w C02.

 

[SupraSPL]

Looking at this chart, the halogen may actually be more efficient than the infrared LEDs and certainly a whole lot cheaper. I am not very informed regarding the flower initiation technique. I am still skeptical but I have not tried it myself and many of the DIYers that are using it are smart fellows so maybe there is something to it.

 

[SupraSPL]

So if yield is your primary mission, the variety will make a world of difference compared to my best LED numbers (1.4gr/W - 610W - 20ft² - 45% efficiency - 5 gal buckets w organic soil - CO2 700-1500 - mid yielding varieties). I believe you could go higher than 2gr/W with a system tuned for yield.

Are you limited by space or heat management? If heat is holding you back it make sense to run softer (~800mA) so you can create as much light as possible with as little heat as possible. But if space is the main thing holding you back, you could crank up the intensity (1450mA) at the expense of efficiency as long as you can move all that heat out somehow. You can run the Veros even harder but it requires the use of more expensive drivers, so an increase in up front cost without the bonus of increased efficiency.

I have been vegging the ladies up larger to try and increase yield (more roots, more fruits theory). Some of them have been finished 4.5-5 feet tall and for the most part I am using overhead lighting. So it may be a better use of space to work in some kind of side lighting on the outside edges of the canopy.

 

[churchhaze]

A halogen at any temperature will likely not be more efficient than a 730nm led because the wavelength needed really needs to be within 10nm or so from 730nm. 800nm will not work, meaning it has to be considered waste.

Only light within a tight bandwidth centered at 730nm can be considered part of the output power for a sleep initiator.

More important than efficiency is how effective it works at causing Pfr to convert to Pr. The gradient of the curve between 600-800nm tells you more about where %Pfr will converge (percent of total phytochromes in the state of Pfr).

Notice with the 2500k incandescent, the gradient between 600nm and 800nm is sharply upward. This means it has a very low R:FR ratio, and will cause serious stretching. The sun, on the other hand, has a downward gradient between 600nm and 800nm, meaning a very high R:FR ratio. That will reduce stretching. Nothing, however, beats a 730nm narrow band emitter when it comes to trying to get a low R:FR ratio, and it will cause %Pfr to converge around 1-5%.

Looking at this chart, the halogen may actually be more efficient than the infrared LEDs and certainly a whole lot cheaper. I am not very informed regarding the flower initiation technique. I am still skeptical but I have not tried it myself and many of the DIYers that are using it are smart fellows so maybe there is something to it.

 

[SupraSPL]

Good info CH. I agree that efficiency in this case is mostly irrelevant, but would the halogen do the job? Also, do you think it is the 730nm flower initiation technique is effective and if so, is there a possibility of any negative consequences of forcing the plant to sleep?

 

[churchhaze]

I've only tried the 730nm once and I switched to a new strain at the same time. I can't tell if it reduced flowering time on C99, but I can tell you that if you use it incorrectly, it will stretch the hell out of your plants. It works to cause stretch!!!

As for halogen doing the job, it will certainly lower the %Pfr from white LED level. Theoretically, if you grow with just 660nm leds, when the lights go out, %Pfr should be around 85% (the highest it can be based on the absorbance curves of Pr and Pfr). The 4100k halogen on the curve you posted shows a R:FR ratio of about 1:1 going by eye, which might not be bad enough to make effective sleep lamp.

I remember trying to use halogens manually at lights out with fluorescent tubes a long time ago (2004?) and i gave up and went back to HPS for flowering before I could really judge. 730nm leds make teh whole process so much easier though. You figure signals is one of the main original uses of LEDS (street lights, remote controls, etc)

Good info CH. I agree that efficiency in this case is mostly irrelevant, but would the halogen do the job? Also, do you think it is the 730nm flower initiation technique is effective and if so, is there a possibility of any negative consequences of forcing the plant to sleep?

 

[Chigur]

Are you limited by space or heat management? If heat is holding you back it make sense to run softer (~800mA) so you can create as much light as possible with as little heat as possible. But if space is the main thing holding you back, you could crank up the intensity (1450mA) at the expense of efficiency as long as you can move all that heat out somehow. You can run the Veros even harder but it requires the use of more expensive drivers, so an increase in up front cost without the bonus of increased efficiency.

I have been vegging the ladies up larger to try and increase yield (more roots, more fruits theory). Some of them have been finished 4.5-5 feet tall and for the most part I am using overhead lighting. So it may be a better use of space to work in some kind of side lighting on the outside edges of the canopy.

Im limited by neither space or heat, If im using Co2 ill have to have the temps high but that and side lighting are things work out once im set up.

So 1450mA? How will that effect the draw? Im roughly basing things on 60w per..Including driver-cooling.

Just looked at Arrow and ts said 100 in the pipeline but says April! Usually how accurate is the order page? I hope bore April or ill be in market for Vero 29's.

So..4 or 5 COB's on a meter long heat sink?...1 or 2 fans?

730nm leds make teh whole process so much easier though. You figure signals is one of the main original uses of LEDS (street lights, remote controls, etc)

So would you incorporate them into the bar or get the flower initiator floods at 200$ each? If on the bar do you know which LED is the best choice and what about coverage?

Anyone used this?
http://www.aliexpress.com/item/Free-shipping-20w-50w-Pure-aluminium-heat-sink-for-multichip-led-cooling-DIY-Led-Grow-Light/1516376547.html

Thanks!!!

 

[churchhaze]

I wouldn't spend 200 dollars on a flower initiator. You can either use epistar 730nm or ledengin, unless there's another brand that makes high powered 730nm leds now.

I use ledengin... i forget what exact model, but I know the price went up. It shouldn't matter how efficient it is as long as it's 730nm, since it will only run for 5-15minutes at lights out.

You can get away with just using a long aluminum flat rod with 3 leds on it. That's what me and positivity do. (i copied his design) CaptainMorgan uses a rebuilt flood lamp of some kind.

So would you incorporate them into the bar or get the flower initiator floods at 200$ each? If on the bar do you know which LED is the best choice and what about coverage?

 

[indianajones]

Im limited by neither space or heat, If im using Co2 ill have to have the temps high but that and side lighting are things work out once im set up.

So 1450mA? How will that effect the draw? Im roughly basing things on 60w per..Including driver-cooling.

Just looked at Arrow and ts said 100 in the pipeline but says April! Usually how accurate is the order page? I hope bore April or ill be in market for Vero 29's.

So..4 or 5 COB's on a meter long heat sink?...1 or 2 fans?




So would you incorporate them into the bar or get the flower initiator floods at 200$ each? If on the bar do you know which LED is the best choice and what about coverage?

Anyone used this?
http://www.aliexpress.com/item/Free-shipping-20w-50w-Pure-aluminium-heat-sink-for-multichip-led-cooling-DIY-Led-Grow-Light/1516376547.html

Thanks!!!

this is a cheaper cooling solution that comes with screws for mounting.

http://www.amazon.com/ARCTIC-Alpine-11-Plus-Cooler/dp/B00606OHQQ

i feel like the arctic 11 plus has become the standard for DIY led builds.

 

[stardustsailor]

I wouldn't spend 200 dollars on a flower initiator. You can either use epistar 730nm or ledengin, unless there's another brand that makes high powered 730nm leds now.

I use ledengin... i forget what exact model, but I know the price went up. It shouldn't matter how efficient it is as long as it's 730nm, since it will only run for 5-15minutes at lights out.

You can get away with just using a long aluminum flat rod with 3 leds on it. That's what me and positivity do. (i copied his design) CaptainMorgan uses a rebuilt flood lamp of some kind.

10 whopping watts of 730 nm FR ,for ~ $22 ...

https://www.kiwilighting.com/10w-ir-730nm-led-emitter

 

[nogod_]

If youre a whore for gpw and your budget is large then really youre a whore for lpw. Best way to achieve this is blanket your grow room in densely packed, softly driven, super high efficiency cobs that perform best when they are under driven.

Look at it this way:
if your target is 3000w of AB @700 mA you are emitting 491,xxx lumens.
@1400mA you are emitting
422,xxx lumens.

You are losing roughly 14% of your light for the same energy burned. Your spread is also much more even with 700mA and you can get closer to the canopy which means less of your photons are ending up in the angel's share.

Great info, i helped sell that 100 out, i have 20 x CXA AB's on the way and a request in for 40 more, not in a huge rush but ill keep the Vero's in mind. Waiting on 6" heatsink bars to come available.

Do you have more info on the Halogens as flower initiators?

Thoughts on bars vs panels?

Sorry but after all this reading im still wondering, with the intensity vs efficiency what is the sweet spot as far as GPW? I know some crank it up to make the buds more dense or what ever, Im not concerned with that nor on the other side driving the units too hard, im a total yield whore. Ill be doing one or two strains w C02.

 

[PurpleBuz]

Good info CH. I agree that efficiency in this case is mostly irrelevant, but would the halogen do the job? Also, do you think it is the 730nm flower initiation technique is effective and if so, is there a possibility of any negative consequences of forcing the plant to sleep?

not sure but I doubt a halogen will work as a "flower initiator" its got too much light in the 600-660 nm range to cause a quick and dramatic shift in the Pf/Pfr ratio. Probably only slightly better than just turning the lights off.

 

[AquariusPanta]

Good info CH. I agree that efficiency in this case is mostly irrelevant, but would the halogen do the job? Also, do you think it is the 730nm flower initiation technique is effective and if so, is there a possibility of any negative consequences of forcing the plant to sleep?

CaptainMorgan would be the best person to ask, as he's got a few years of experience behind using infrared (IR).

I'm currently using 2x (IR)s for a single lady. For about a week straight and with the infrared turned on after lights out, she would would grow around two inches per night on average, with a high of three inches and a low of one inch. While this rapid growth and stretching may be viewed as a negative outcome, I believe it sped things up for her and allowed her early flowering phase to end sooner, thus bringing forth budding many days before if I had not used infrared. CaptainMorgan personally told me that this was something he experiences as well. He seems to get pretty decent/above average yields.

A link to my source of (IR) stars:
http://shop.stevesleds.com/EpiLEDs-Hyper-Far-Red-3-Watt-LEDs-8794102487.htm

 

[Chigur]

I
You can get away with just using a long aluminum flat rod with 3 leds on it. That's what me and positivity do. (i copied his design) CaptainMorgan uses a rebuilt flood lamp of some kind.

Great, what kinda coverage with the ledgin?

i feel like the arctic 11 plus has become the standard for DIY led builds.

Yup, got 5 on order for my spotlight cobs, if i build bars ill only need 1 fan per 2-3 Cobs. My is my plan using 6" Heat sink bars from heatskinusa. You think im better off tacking Spotlight Cobs w/Attic cooers to Aluminium bars?

10 whopping watts of 730 nm FR ,for ~ $22 ...

https://www.kiwilighting.com/10w-ir-730nm-led-emitter

Thanks...I wonder about the coverage,,,10 W, This is the style i have seen before..Why i was asking about a lens to spread out the light.

CaptainMorgan would be the best person to ask, as he's got a few years of experience behind using infrared (IR).

A link to my source of (IR) stars:
http://shop.stevesleds.com/EpiLEDs-Hyper-Far-Red-3-Watt-LEDs-8794102487.htm

Cheers, the price is right, What kind coverage do the provide? 2 per plant is a tough guide!

Thanks