DiY LED - Cree CXA3070

SupraSPL said:

I suppose that what it comes down to is how much work you are willing to do. The 3070s are very easy and quick to assemble (except the sanding part if you plan to flatten your heatsinks). There is no doubt that 3000K produces great results on its own. That said, adding some deep red and deep blue may improve the quality of the buds even further but increases complexity. So I settled on something like this (COBs should be spread further apart)

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When I was mixing HPS with LED I set them up side by side because the HPS needed to be so far away from the canopy that the LED modules would block the HPS light. Another option is to surround the canopy with LEDs and HPS in the center. So mounting the COBs up high with the HPS would be problematic. For reference my COBs are only 8-12" from the canopy.

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I run 600s at the same distance.

SupraSPL said:

I suppose that what it comes down to is how much work you are willing to do. The 3070s are very easy and quick to assemble (except the sanding part if you plan to flatten your heatsinks). There is no doubt that 3000K produces great results on its own. That said, adding some deep red and deep blue may improve the quality of the buds even further but increases complexity. So I settled on something like this (COBs should be spread further apart)

View attachment 3139410 View attachment 3139408

When I was mixing HPS with LED I set them up side by side because the HPS needed to be so far away from the canopy that the LED modules would block the HPS light. Another option is to surround the canopy with LEDs and HPS in the center. So mounting the COBs up high with the HPS would be problematic. For reference my COBs are only 8-12" from the canopy.

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complexity isnt an issue, im a service tech by trade so im good there, I just dont know what way I should go. I can pull a pound per 600 pretty steady, id like to bump it up to say a pound and a half with supplimented diy led for the extra frost, im not against going complete led but I dont know. I run my 600s around a foot so the 3070s would work but I guess I dunno if 4 big r-w-b panels would be a better bet than either hid+3070s or all 3070s. I dont ask for advice very often here but this question has me stumped. what would be your ideal set up to pull a pound n a half out of a 4x4?

Gotcha I was running my 600s bare so they were probably 18" from the canopy. My yields werent as high, .75LB from a 600 when the bulbs were brand new (organic soil setup). You are definitely working your 4X4

Theoretically, you should be able to add another half pound with ~200W LED. So you could use (4) CXA3070s at 1.4A each and separate them onto 4 CPU heatsink/fans.


Or you could use the big heatsinkUSA modules like these and really cram light in there. 4 of these big modules (832W) in a 4X4 would put a lot more light into the canopy than a 1000 HPS and theoretically should yield 700-800grams of connoisseur nugs.

SupraSPL said:

Gotcha I was running my 600s bare so they were probably 18" from the canopy. My yields werent as high, .75LB from a 600 when the bulbs were brand new (organic soil setup). You are definitely working your


Or you could use the big heatsinkUSA modules like these and really cram light in there. 4 of these big modules (832W) in a 4X4 would put a lot more light into the canopy than a 1000 HPS and theoretically should yield 700-800grams of connoisseur nugs.
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I have no problem running 4 of them if thats the answer, I already had that thought thats why I previously said 16 3070s, so your thought is 16 3070s will be better than a 600 with 6 3070s or a 600+rwb or a 600+3070s+rwb? Im willing to go all in with led if someone such as yourself endorses it. 16 3070s would be a breeze and I wouldnt bitch at all as long as I pull an extra 8 ozs over a 600. Passive or active cooling for longevity? In your opinion if I took a magnum hood, replaced the glass with aluminum, added 4 large heatsinks with 4 3070s each, and used my hood as designed pulling in a carbon filter, to the hood and over the fins, is that a feasible option? Im just spit ballin here so any thoughts are appreciated. As far as my 600 runs go, I honestly dont think its anything special, just 4 4 oz plants. And I run hydro and thats a breeze at this point so that helps, gonna bust out an organic run this time tho, soils mixed and has been cookin in the Florida sun for a week now, bring on the bugs!

That sounds awesome I would love to see what you can do with 16 3070s in a 4X4. Yes I do believe you can safely phase out the 600 and I can guarantee you will have more than 2X as much light in the canopy. But I can't guarantee what the the yield will be in a 4X4 because I spread my wattage (500) into a wider canopy (4X5) and you would be putting 832W into a 4X4. From what I understand you will get larger buds that way but overall efficiency decreases as we increase PPFD. Also, it may take time to dial in the ferts, more light means hungrier ladies. I have found that mine like to fade early on me if I neglect N, depending on how big I vegged them up and depending on the variety. And finally it depends on the variety, airflow/CO2 etc.

So ultimately it would be experimental, but no risk of lower yield. As far as ventilation goes, your suggestion would work great keeping the heatsinks cool but Im thinking it would reduce the light spread and the adjustability of each module. Do you have a separate ventilation fan or is the hood sucking air from inside the tent? Another option, if you removed the glass and reflector and just had the carbon filter sucking from the top with a passive intake toward the bottom. You could use big PC fans to cool the heatsinks using about 24 Watts if you really crank them.

Ken's Bay11 that was under 3000K CXA3070. Nice big frosty dense nugs about 15" deep but not a keeper for me. It strong and nice smell but compared to the best, it is missing the funk. You can see some unsightly dreading as well which seems to show up more in some of the ladies that pack on the most weight.

Reserva Privada Kandy Kush that was under RWB. Super stinky skunk OG lemon cake smell, one of my top 5 favorite ladies.

Cali Connection Purple Chem - raunchy OG fuel - green pepper/onion skunk

Nice plants Supra, I like seeing what these COBs can do. Cant wait to flower my own under them. Couple more weeks...

I could tell the 3000k CXA spectrum was different from the HPS but didnt know how different until I had both veg and flower tents open at the same time the other day and I thought it was a good picture to take to show the color difference of the 3000k CXA vs a standard 150w HPS bulb.



Maybe a little off topic but we can take a peak in the flower tent at day 53 12/12 and see what the 2 3070s will be going up against.

Are these the right Z4s all you LED gurus are talking about? http://www.digikey.com/product-detail/en/CXA3070-0000-000N00Z450F/CXA3070-0000-000N00Z450F-ND/4386668
Shopping around today to order a couple for my 2 plant flower chamber in my cabinet. $38 each at digikey seems like a reasonable price.
3.5 sqft foot area to cover, I'm thinking 2, maybe 3 cobs will be good? If anyone has a line on a cheaper non-bulk CXA3070 supplier post up!
Can someone explain the "top bin/mid bin" terms?

Haven't decided what size drivers to use yet, the chamber is vertically limited to ~3.75ft of growth height above the DWC tank. Ideally I'd like to have the COBs putting out enough light to just mount them to the roof of the box and keep them there the whole grow, but if that is not realistic I'd be fine using my light hangers to be able to fine tune the distance to canopy.

You guys are pioneers for the future of indoor growing, pretty awesome how you're all using cutting edge tech for ganja! I hope to join in soon.

SupraSPL said:

Cali Connection Purple Chem - raunchy OG fuel - green pepper/onion skunk
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what heatsink would you suggest for 4 3070s with passive cooling? I run a fan up top and down low as well as my 440 exhaust running 24/7 so I have a ton of air exchange. So if you follow me im thinking 4 heatsinks with 4 3070s each. Also would you suggest running 4 of the 5000k and 12 of the 3000k(or whatever the exact n
K numbers are) or what? I want a veg/flower rig and my simple hid mind tells me I need more blue than a 3000k will provide. Im not not the brightest bulb in the pack when it comes to the entire led thing so I apologize if you have already answered that before, I just want to put an order in tomorrow and am looking for some insight.

nolem1234 said:

Are these the right Z4s all you LED gurus are talking about? http://www.digikey.com/product-detail/en/CXA3070-0000-000N00Z450F/CXA3070-0000-000N00Z450F-ND/4386668
Shopping around today to order a couple for my 2 plant flower chamber in my cabinet. $38 each at digikey seems like a reasonable price.
3.5 sqft foot area to cover, I'm thinking 2, maybe 3 cobs will be good? If anyone has a line on a cheaper non-bulk CXA3070 supplier post up!
Can someone explain the "top bin/mid bin" terms?

Haven't decided what size drivers to use yet, the chamber is vertically limited to ~3.75ft of growth height above the DWC tank. Ideally I'd like to have the COBs putting out enough light to just mount them to the roof of the box and keep them there the whole grow, but if that is not realistic I'd be fine using my light hangers to be able to fine tune the distance to canopy.

You guys are pioneers for the future of indoor growing, pretty awesome how you're all using cutting edge tech for ganja! I hope to join in soon.

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Those are 5000k Z4 bin in the digikey link. For flower you would want 3000k most likely. On ebay there are 5 CXA3070 3000k Z4 bin left, which is top bin/most efficient available.

My tent above is 1.5x2.5ft= 3.75 sq ft before the exhaust sucks the sides in a bit. Im going with 2 3070s, I think you would be good with 2 COBs but 3 would be excellent.

Bueno Time said:

Those are 5000k Z4 bin in the digikey link. For flower you would want 3000k most likely. On ebay there are 5 CXA3070 3000k Z4 bin left, which is top bin/most efficient available.

My tent above is 1.5x2.5ft= 3.75 sq ft before the exhaust sucks the sides in a bit. Im going with 2 3070s, I think you would be good with 2 COBs but 3 would be excellent.

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Thanks Bueno, I put in an offer lower than the $53 list price for 3 of those ebay ones. If that doesn't go through I think I'll go with the Z2s which are $10 cheaper, or are the Z4s worth it? I think I remember somewhere earlier in this thread there was a comparison of the two and the Z4s are better, but not by too much

For passive cooling I can only install about ~60W on my large heatsinkUSA heatsinks (10.08" X 6") to maintain low temps. Low temps are worth pursuing (IMO) because it directly affects efficiency and lumen maintenance. After some testing with active cooling I discovered that I could install well over 100W on that same heatsink and achieve even lower temps, with heatsink fans running quietly/soft. So based on that I highly recommend active cooling even with the big sinks.

I suspect we could install 208W on a 10.08" X 6" heatsink and I can test that theory to make sure. You can use passive cooling but it requires quite a lot of heatsink. To passively cool 832W it would cost about $850 for the heatsinks and they would measure 10.08"X8.5ft, cut into what ever lengths would fit. Assuming my theory is correct, for active cooling the cost would be ~$200 (10.08" X 2ft) including the heatsink, fans and fan power supply.

Regarding the color temp, I agree most varieties would benefit from (a lot) of extra blue in veg. You could shut down some of the 3000Ks and add a few deep blues. The deep blue Luxeon M is available from Steves LEDs and it dissipates 8 Watts @ 57.7% efficient.

Unfortunately the 5000K CXA3070 we have available to us is the lowest bin in that color temp so the efficiency is not where it should be for a 5000K (39.4%) @ 1.4A. The 4500K XML2 for example is 46% efficient at 1A.

That said, the 5000K CXA3070 will kick some vegging butt and you don't need much power to get the job done. On the other hand maybe if you really crank the power in veg it will get you into flowering stage much quicker.

Bueno those ladies look pretty awesome, HPS is tough competition.

SupraSPL said:

Bueno those ladies look pretty awesome, HPS is tough competition.

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I know it is going to be very tough for the 2 3070s @ 1.4A to beat the 150w HPS but I think it could be possible.

Yes they sure will The 150HPS does not get the benefit of the very high levels of efficiency that the 600 and 1000 get. I would dare say that 104W of CXA3070 would almost double the yield of the 150 HPS.

(In advance, please forgive me if this has already been covered).....

Yo Super!? I see lots of led drivers on Ebay that are "Constant Voltage". For our COBLED projects, I understand that we use/need "Constant Current". I don't get it? What is the purpose/use of the "Constant Voltage" for LEDs?

Thanks

CobLedz said:

(In advance, please forgive me if this has already been covered).....

Yo Super!? I see lots of led drivers on Ebay that are "Constant Voltage". For our COBLED projects, I understand that we use/need "Constant Current". I don't get it? What is the purpose/use of the "Constant Voltage" for LEDs?

Thanks

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Not supra, but... Think of things that need a certain voltage (ex. computer fans), you can hook up multiple fans for that same voltage and only use one power source that's what a constant voltage driver is for. Led's need a constant current to make sure they don't exceed their max as you know, leaving no real need for a constant voltage driver for them. You could run them off of it, but it would require much more work/skill to build.