New LED Grow - Advice Needed

Couch_Lock said:

They are undoubtedly the most efficient lights around, Chip.

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More efficient than Samsung strips, using the the same Samsung diodes?

Chip Green said:

This is a source of great debate. That aside, I contend if you have the willingness to drop the level of cash needed for that many cobs, a good move would be to look at Cobkits com.
He's also an advertiser on this site.

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So I just made a quick analysis based on the the info docs provided for the:
>Cree CXB3590, Luminus CXM-32, Citizen CLU58 1825 (the Bridgelux Vero 29 doc was too much of pain to read so i gave it up)

What I did...

1. Work out wattage consumed at various currents (0.7A, 1.4A, 2.1A, 2.25A)
> equation: Watt = Current x Typical Forward Voltage (Cree 36V, Luminus 51V, Citizen 51-52V)

2. Then I calculated Lumen per Watt
> equation: Lumen per Watt = Typical Flux (at 85˚C and 25˚C) ÷ Wattage

Assuming the data in the info docs is correct, that I read it correctly, and that I calculated it correctly... this is what I found:

CRI / Kelvin / Winner
90 2700 : Cree
90 3000 : Luminus
90 3500 : Cree
90 4000 : Luminus
90 5000 : Cree
90 5700 : Cree

80 2700 : Citizen
80 3000 : Citizen
80 3500 : Luminus
80 4000 : Cree
80 5000 : Cree
80 5700 : Cree
80 6500 : Cree

70 4000 : Cree
70 5000 : Cree
70 5700 : Cree
70 6500 : Cree

(i cant upload spreadsheet - 'extension not allowed')

Renfro said:

Why the 5000K? I would think a 3500K for all would be good, or perhaps a mix of 3000K and 4000K.

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Growmau5 suggested a mix of 5000K & 4000K for veg. growing Seems like a good suggestion. Apparently having the mix of the two gives a little more space between nodes (4000 & 5000K having more blue light)

Couch_Lock said:

34 Cree cxb3590 2700K 90 cri
33 Cree cxb3590 3500K 80 cri
33 Cree cxb3590 5000K 70 cri

Hella money but probably a killer spectral setup. Tight internodes (blues), lots of red for flower.

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Then for flowering maybe some combo of 3500,3000,2700K
But your right to cost would super high.
Especially if i run the cobs at a higher current for flowering - because then I need to buy all new drivers as well...

Cob calc can be found here
https://www.rollitup.org/t/diy-cob-led-calculator.890214/page-14#post-14701729
Use the link in bggrass 's signature, below any of his posts. You need java to run it.

Thanks im gona look at this now

When I was an entry level DIY LED builder, I spent countless hours staring at data sheets, obsessing over efficiency and K temp combinations.....I eventually got nauseated with all the indecision, and committed to Bridgelux Vero SE, because they don't need extra holders, for my first COB build. I arbitrarily became brand loyal to Bridgelux, and moved on to the even simpler option of the strip style emitters....After several more builds, and many perpetual grow cycles of the same known strain, that had been run using a somewhat absurd number of K temp combinations, I began to get the impression, the difference between 3000K, 35000K, 4000K ect, was mostly negligible for my purposes....All in one, good ol' 3500K now rules my roost....
I have multiple racks of these things.... some of them I really have no idea what the K temp is, probably something like 3175, er so...
I, personally have never had any evidence to declare that one number is better than the rest, other than pricing, which became the deciding factor for me ...In no way am I saying that they will NOT display different properties, I just generally find it, as splitting hairs...
The beauty of DIY is that the design possibilities are endless. At times, endless to an extent that became counterproductive, due to my insatiable desire, to fuckin tinker with the damn lights...

Welcome into the wormhole, by the way.