Lighting DIY COB Based LED Growlight Build In Progress!

[pop22]

I think with white LEDs, people get too hung up on spectrum. I've seen guys grow quite well with 5000k chips, yet looking at that chart, you'd say no way! For growing, get what you can afford the amount of gain or loss thru cri isn't worth worrying about, it is important to the lighting industry because of the way we see.

If 3500 or 4000k chips had been cheaper, I'd have used them.

 

[Atulip]

And consider hps is like 20cri and peaks in yellow. We been growing under them just fine.(I'd still prefer hps over less efficient leds)

I've been wanting to do a grow solely under 5000k. They have the highest light output and the widest spectrum. I wonder if someone's done a side by side. I'd be curious to see how like a 6500k vs a 3000k 90cri would compare. Raw light output vs optimal spectrum.

 

[pop22]

You hit the nail right on the head! Efficiency! I see comments here already that makes me think they are going to run the leds at max current! NO! running good COBs at 40-60% of max current rating, gives the best efficiency and extends the life of the chips. Running this way, people are getting close to or even over, 2 grams per watt! With the right setup and plant traing, 3+gpw should be achievable.

And consider hps is like 20cri and peaks in yellow. We been growing under them just fine.(I'd still prefer hps over less efficient leds)

I've been wanting to do a grow solely under 5000k. They have the highest light output and the widest spectrum. I wonder if someone's done a side by side. I'd be curious to see how like a 6500k vs a 3000k 90cri would compare. Raw light output vs optimal spectrum.

 

[Symbolic]

80cri would be shifted slightly more to the red but also about 10lms/watt less efficient. Pretty close but I'd probably just go with which is cheaper.
View attachment 563108

ye, from 630nm ur looking at 15% less red from the 70cri. which i agree w/ u at the price.

 

[Atulip]

I want to chime in and say gpw is highly subjective though. You'll gain a higher gpw simply by running lower light over larger space. (600w over a 4x4 yields more than a 600w over a 3x3) 1gpw was the baseline for a good hps grow, 1.5gpw becomes that figure for most cob upgrades(same yield, less watts).

The main thing with efficient leds is replacing our current amount of light with less watts. I never tell anyone to expect a better yield, you should start with the proper amount of light for your space. Cobs just offer more lumens at less watts, directional with little to no reflection loss, and a longer life. But if I had to chose between the proper amount of hps lighting, or half as much led lighting as I need, I'd go with the hps. Increased yields will outweigh what you save on extra electricity and bulbs.


Anything below 110lm/w isn't really gonna be much better than a decent HPS. With cobs, you'd still save money from HID replacement bulbs, a lot of the cheaper leds won't last long though. Above 150lm/w is where you want to be to beat an hps for unreflected light output(usually where we compare a reflected 600w hps to around 400w Cree cob setup) for most with the bar design, the added evenness of the spread also accounts for a lot compared to single center hps fixtures.

 

[pop22]

Yes, and I mentioned gpw only as a reference point for most people.

COBs ran efficiently will match hps on a watt for watt basis. Ran hard, they can exceed the output of hps. Go on youtube and see Growmau5's video of his DIY LED vs HPS grow results. And that first one is with CXA3070's I believe. The cobs with lower lumen ouput compete as you say, by providing a more even spread of the light.

I'm building my light specifically for scrogs. it is meant to run close to the top of the canopy. From seeing others, 8" to 12" in flower. When I add the fourth bar, I'll have 20 cobs spaced over a 4'x4' area. Power consumption is estimated to be 460watts. My goal is 1gpw, with expectations of exceeding that. Now, ad a vertical scrog net on 2 of the walls of the tent, each with its own light. I've double the canopy area and still using less than 1000 watts of power to do so. The only way to match that with HPS is silo style, which does not work well in a small tent, air circulation/heat removal issues. With 2 flat vertical screens you can maintain good air movement over the canopy.
And in the coming months, I'll be putting this into place. My goal is to eliminate, one of the two 4x4 grow spaces and reduce plant count to 2

I want to chime in and say gpw is highly subjective though. You'll gain a higher gpw simply by running lower light over larger space. (600w over a 4x4 yields more than a 600w over a 3x3) 1gpw was the baseline for a good hps grow, 1.5gpw becomes that figure for most cob upgrades(same yield, less watts).

The main thing with efficient leds is replacing our current amount of light with less watts. I never tell anyone to expect a better yield, you should start with the proper amount of light for your space. Cobs just offer more lumens at less watts, directional with little to no reflection loss, and a longer life. But if I had to chose between the proper amount of hps lighting, or half as much led lighting as I need, I'd go with the hps. Increased yields will outweigh what you save on extra electricity and bulbs.


Anything below 110lm/w isn't really gonna be much better than a decent HPS. With cobs, you'd still save money from HID replacement bulbs, a lot of the cheaper leds won't last long though. Above 150lm/w is where you want to be to beat an hps for unreflected light output(usually where we compare a reflected 600w hps to around 400w Cree cob setup) for most with the bar design, the added evenness of the spread also accounts for a lot compared to single center hps fixtures.

 

[Ozone69]

I wouldn't say that the main thing for LED vs HID is lowering watts or power consumption in everyone's case. For many, many folk it's as much about lowering heat generation as anything else. If you've converted an unused closet like I have, going LED meant not having to plum in ventilation to the attic or outside to manage temperatures in the space. Efficiency has more benefits than just lowering your power bill. :smoking:

 

[keep pounding]

the popular mean well driver that is used (hlg185c1400b is what I use) is getting scarice. a lot of suppliers do not have in stock and will be 1/2 -1 month out.
I wonder why that is? LOL
finally found in stock at Sager. will let yall know how sager takes care of me, with my first order from them.
my 1st drivers came from onlinecomponents and all went well.
just used Newark for my cob holders and adaptors, 1st time with them and will let yall know how that goes.
hopefully all goes well so my 3rd light bar will be started on soon.

appears that sager and Newark have a high starting point on shipping.
Newark charges like 10 bucks and if it is heavy it goes up. same with sager, but sager charged 18 bucks to ship 1 mean well driver. that is steep. all items came like they should. and heatsink has a 10% discountcode for may code is GIVEMETEN
now looking for good price on cxb 3590's 3500k

 

[Ripper]

appears that sager and Newark have a high starting point on shipping.
Newark charges like 10 bucks and if it is heavy it goes up. same with sager, but sager charged 18 bucks to ship 1 mean well driver. that is steep. all items came like they should. and heatsink has a 10% discountcode for may code is GIVEMETEN
now looking for good price on cxb 3590's 3500k

You find a good price let use know.. Cheapest I have seen is $40.00 on Alibaba

 

[keep pounding]

will do rip.
cheapest cobs in U.S. I have found is at pacific light. never ordered from there yet. seems a lot of stuff there is out of stock.
may try the Alibaba route. how has Alibaba been for others?