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The DIY COB Addiction

jimmyclone

On Vacation
So people that dont know, quality cobs are the most amazing grow lights available for the price, Hands down. Efficiency, spectrum, control, customization. I wanted to share my build and time with these little gems.

Lets look at the spectrums here first.
The McCree curve is what we are trying to achieve here

You can see that cob lighting fills much more of the gap than hid. Now there are many more options for cob spectrums than what is shown here. Vero now actually has a 1750k chip.. Then we have 70,80,90 cri options.. I did say customization..

Here is an efficiency chart comparing some of the most common quality cobs.


So lets go through some of my build..

16x vero29 se 3500k
4x meanwell hlg240-1750 b drivers

Built into 2 36"*36" panels to go in my 8*8 tent. I only use a 4*8ish space inside.



So i went from 1000w hps at around 20" away to 330w over 8 cobs at 30-36" away on my 2 final girls from last run and in 12 hrs they were showing severe signs of light stress. I had more tacos then the local burrito shop.. So down to 250w i went and they were praying like they never had b4.. Extremely powerful little things.

Now these really aren't that hard to build.. Much , much cheaper than high end prefab leds, and you can easily get a much higher ppfd for your grow space.. And if you dont want to tackle the build yourself you can order a timber kit in the US (pretty expensive though) or there is a guy on here from canada that builds and sells quality cob panels. Also check out autocobs, great guy with a quality product as well. If your going to try to build one, Rapidled.com is a great place to start, they have everything you need to get going besides aluminium angle..

Please, please, please, people, think twice about buying blurple crap..
White light is the way forward, blurple was a bad mistake...

Thank you
White Light Warrior
 

Obi Wan

Well-Known Member
I'm interested in building an efficient fixture. Would you do anything differently now that you have a build complete?

I notice you dial yours down a bit to prevent stress. Might you consider a different wattage chip or is the Vero29 in it's sweet spot where you are running it?

Cheers!
/Obi
 

jimmyclone

On Vacation
The lower you run your chips, usually the more efficient they'll be. I have mine dialled down because at 330w my girls were showing signs of light stress.. And they used to be under 1000w hps.. Thats how much power these things have.. Also i wanted to have more than enough wattage and not regret it later.. The only thing i would have done different would be to mix 80,90cri of the same spectrum.. So i would have done 4x 80cri vero29's, and 4x 90cri vero29s all 3500k per panel.. I just ordered up 4 vero29s 2700k 90cri(tons of far red) to swap out my middle 2 cobs on each panel... The 90cri in any spectrum have more far red or deep red..
Cheers
 

jimmyclone

On Vacation
I wish i knew this all before i buy a led light from mars hydro !
Ooouch... I almost made that mistake as well.. Gotta do ur homework b4 any big purchase man... Its ok, you'll be wanting real leds very soon... Im sure of it..
Cheers
 
Ooouch... I almost made that mistake as well.. Gotta do ur homework b4 any big purchase man... Its ok, you'll be wanting real leds very soon... Im sure of it..
Cheers
I did some big research and i tought it was tougher than this to make but anyway my mars reflector 192 with 5w chips was fitting my budget and as i can see it is not a bad light at all but when i'll build another setup for perpetual grow for sure i will build my own light !
 

Justwannagrow

Well-Known Member
I have a question since you brought up the cri, are all of your lights 80 or 90cri and are they the 36,50, or 72v versions.. I'm about to build one myself using the vero 29s so I'm subbed
 

jimmyclone

On Vacation
I use the 36v vero29's.. I have 12 3500k 80cri and 4 2700k 90 cri.. I had 16 3500-80's until i saw this comparison thread.. Now im swapping 4-80's fo 4-90's in the center of each panel..
Here is one of my panels..
 

jimmyclone

On Vacation
If your going the 50,72v way u should get a constant voltage driver and wire in parallel.. Unless you want to buy a ton of drivers... If your going 36v you can get a constant current driver and wire in series..
 
I use the 36v vero29's.. I have 12 3500k 80cri and 4 2700k 90 cri.. I had 16 3500-80's until i saw this comparison thread.. Now im swapping 4-80's fo 4-90's in the center of each panel..
Here is one of my panels..
Where can i find the between 80 and 90 cri ?
What does it mean betwen 80 and 90 cri
 
I'll sure be looking for 90 cri on my build :) might be in a few months [emoji14] i curently have a reflector 192 with 5w chips, works well but it's my first grow so i will learn along the way !
 

Justwannagrow

Well-Known Member
Yeah the 90 cri peeks at 630nm where the 80 peeks at 600nm. But the 90 has less lumens but the way I see it most people are turning them down anyways, I'm not sure exactly what I'm gonna do exactly but I do know I'm gonna use 90cri, it's the drivers and heatsink combos that I'm still in debate about
 
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