MCs Grow Chamber

Hello everyone,

I'm putting together a 4x4 tent. I'm looking to build an LED light to maximize production in the tent and grow the highest quality I can. I've seen some nice designs on here and I was hoping for a bit of guidance. I'll be doing an organic soil grow and if I'm honest, Supra's set-up is what I'd like to mimic.

Which COBs should I buy? Which heatsinks? Which drivers? What additional tools do I need? Would you be willing to give me links to any of these items? I've looked on Kingbright but the selection is overwhelming, especially for someone who doesn't really get how the bins are rated.

Any guidance the forum can provide is greatly appreciated. We'll keep this thread updated as I build and I'll post my DIY and questions as I go along building.

I wish everyone peace

Mary's Confidant said:

Hello everyone,

I'm putting together a 4x4 tent. I'm looking to build an LED light to maximize production in the tent and grow the highest quality I can. I've seen some nice designs on here and I was hoping for a bit of guidance. I'll be doing an organic soil grow and if I'm honest, Supra's set-up is what I'd like to mimic.

Which COBs should I buy? Which heatsinks? Which drivers? What additional tools do I need? Would you be willing to give me links to any of these items? I've looked on Kingbright but the selection is overwhelming, especially for someone who doesn't really get how the bins are rated.

Any guidance the forum can provide is greatly appreciated. We'll keep this thread updated as I build and I'll post my DIY and questions as I go along building.

I wish everyone peace

Click to expand...

If you want an efficient setup, copying Supra is the way to go. I think the most efficient setup you can go with right now for a flower room would be CXB3590 3500k CD bin cobs run soft (less than 1amp). If lower upfront cost is more important than efficiency, you could go with Vero 29 4000k COBs run harder (2amp). CXB3070s are a good middle option too.
Most are driving cobs with Mean Well HLG series drivers. Download the spec sheet for cobs you want to use, and look at the voltage forward (vf) for the cob at the amperage you want to run them at. This tells you the volts each cob will use. The drivers will have a voltage range that they operate under, so the sum voltage of your cobs must fall within the range.
The Cree cob spec sheets will tell you the lumen output for the different bin code. The higher bin cobs will put out more light per watt. Vero doesn't use bin codes, so you just order the Vero you want.
If you are in the US, HeatsinkUSA is popular. This thread ( https://www.rollitup.org/t/heatsinks-for-diy-led-lamps.851907/ ) has a lot of great info on figuring out what size heatsink to go with based on how many watts you are dissipating from the cobs. Many will use CPU heatsinks to mount single cobs to, which give flexibility in positioning the light, but offers less protection to the cob if a fan fails. Larger heatsinks can be run passively (no fans on the heatsink, but some air movement in the room will help keep the sinks cooler).
Some of the other guys are better at crunching the PAR #s and how much wattage you'll need, and that will vary based on what cobs you choose.
A bit of homework is required to understand the basics, but once you do it's pretty easy to put together a light. The only problem is it's addicting. I'm halfway through my 1st run with a Vero 29 light and I'm already wanting to upgrade it to CX3590 to bump my efficiency up from 45% to 64%. Less electric, less heat, but spending more $$ on cobs...

I agree, though I would never build an (expensive) LED-Setup that doesn't exceed the highest possible HPS efficiency, which roughly is an initial 42% (so no Veros above 50W). There are, of course, some additional benefits for using LED over HPS, like better light directionality, better spectrum, better spread and less needed heatspace. But you probably would want to build a fixture that is state-of-the-art and lasts for a good while. That may also spare you another addiction.

Thanks BYC and Meinolf,

Does this link look correct for the COBs? http://kingbriteled.en.alibaba.com/product/60259719620-801574224/CREE_CXB3590_3500K_CD_CXB3590_0000_000R0HCD35G.html

I'm going to place an order as soon as I have confirmation.

Meinolf, I agree. I'm going for efficiency to actually have the value of COBs realized, otherwise I'd just purchase an HID unit.

Mary's Confidant said:

Thanks BYC and Meinolf,

Does this link look correct for the COBs? http://kingbriteled.en.alibaba.com/product/60259719620-801574224/CREE_CXB3590_3500K_CD_CXB3590_0000_000R0HCD35G.html

I'm going to place an order as soon as I have confirmation.

Meinolf, I agree. I'm going for efficiency to actually have the value of COBs realized, otherwise I'd just purchase an HID unit.

Click to expand...

I think that's correct - I haven't ordered from Kingbrite, but I'm on his mailing list that he sends out to show his inventory (his email is jl@kingbrite.cn ). You can email him what you are looking for, and he can quote you a price.You'll probably want the cob holders for the CXB3590 too - not sure if Jerry sells them or if you'd get them elsewhere. Maybe @REALSTYLES can help with that - he's buys cobs from Jerry by the case lol.

Jerry is easy to deal with. Very nice guy and will always do his best and yes he has the holders as well.

Thanks Real and BYC, appreciate the help and vouch of approval.

How many 3590s would you attempt to pack into a 4x4 or 5x5 tent? I want high(er) efficiency but I'm not trying to max it out. I'd prefer to keep it "passive" but I'm looking into having a fan aiming at the heatsinks. from below and I'll be pulling air from the tent through a carbon filter so there'll be air turnover.

I'm gonna roll out a 3590 build using the 3500k CDs and try and use 5 cobs on a passive hs. Definitely seems that running them soft is the way to go for me, so using the MW-HLG series is prudent ,imo. But...there's always a butt...I noticed Reals cornering the market on the 72v's (stab at hyperbole) and it got me to thinkin' bout which MW driver I need to go with if I'm going 36v. I'm full-on retard when it comes to maff/numbers/symbols/algea-bras and shit, so any help or observations would be mind-blowing. Factor in age, the pace at which this tech is blowing up and the aforementioned mental handicap and you could probably write-off you time as some sort of charity on your taxes.

Can anyone explain the difference between CXB and CXA? And do most of you DIYers use the 36 or 72v variety? About to place an order for an assortment of 3590s.

Well, it's hard to believe this was originally posted nearly 4 months ago. I've done a great deal of reading and planning since then although many details have yet to be hashed out.

I want to run a small perpetual grow for personal meds. I'm looking at a 5x5 flower spot and a 2x2 or 3x3 veg. I'll use the 5x5 for veg and flower for the first run.

With that said, here's what I've designed so far:



I want to run a few different spectra and I want to run them soft, most likely at 700ma. I have no interest in commercial production or pushing the limits, just want to grow the highest grade meds I can.

If any of the more knowledgable growers would like to chime in on this design, I'd be very thankful.

Here is one more diagram with the mixed spectra:



Green = 3500k
Sky blue = 5000k
Purple = 5700k
Red = 4000k

The only thing I don't like is the uniformity across the middle. I may be better served by replacing the two middle bulbs with 5000ks or another mix.

Im not sure if you need so many different spectra.
People have great success with 3500K alone for veg stage as well.
I wont say what is better as I dont know however.
Either way you go I am sure it work great

I personally after vegging with 3000k would either run 4000k straight through or put every other one 3000k and the others 5000k. Run them on separate drivers so you can use the 5000k for veg and then crank them all up for flower. Or crank the 3000k up and turn down the 5000k a bit. Either way you will be happy. 3500k might be alright as well for vegging. Probably better then 3000k. I vegged with 3000k this round and was actually pretty happy with it. You can check my journal under hps killer for how the veg turned out. Either way you will be happy with the cobs. Good luck!

My other idea would be to add the 5000k in between your bars of straight 3500. Like 4 running at 75w. Just for vegging. Then when flower hits dim them down to 25 and turn on the rest of the fixture.

This is what I'm thinking. 315 in the middle, 12-14 LEDs around the periphery. With 14, the difficulty will be in sizing a driver adequately so it's still maxing out efficiency. Any suggestions on that?

14 CXB3070 BB bin @ 700ma would add how many useable watts/par watts?
14 CXB3590 CD bin @ 700ma would add how many useable watts/par watts?

i was thinking it'd be somewhere in the vicinity of 300-400 additional watts. LEC would be good for a 3x3 area raised 18-20" above the canopy. You could raise it higher but I think the main benefit LEC has over LED would be penetration (at least judging from the thickness of the buds produced). That would start to be wasted the higher you raised it. It would probably be better to let the 315 cover the inner 3x3 and use the LEDs to fatten the outer plants/branches.

If anyone would like to add some calcs to this, I'd be interested in seeing them. This is the design I'm going to run with first (although I'm still unsettled on number of COBs needed for the perimeter). I may change down the line but this will strike a nice balance between efficiency, penetration and it'll be fun to see how it produces.


I posted this in the LEC thread but I thought I'd post it here. Where do we find the numbers on 3070 BB or 3590 CD @ 700 mA? Just trying to get a feel for total watts/par watts.

Any suggestions on drivers for 12-14 COBs @ 700?