COBs + ChilLED 100w PCB DIY

Odindris

Member
I would never use 6500k cobs, even in a veg only tent. It's just way too much blue and you might find that your plants are too compact and might even see morphogenic issues. 3000k is great for veg, though my blurples grew more compact than 3000k for sure. 3500k is perfect for veg, and maybe even 4000k if you really like compact plants. I feel a 50/50 mix of 3000k and 3500k (what i use in my tent) makes the plants grow the perfect strechiness. Compact enough that you get lots of tops, dense growth, thick stems, and good leaf size but stretchy enough that lollipopping/trimming isnt an insane undertaking or to block airflow in the canopy and to make it easy to see issues.

Blue is also more stressful to the plant because it's high energy (almost UV).Having the crazy amount of blue that 6500k cobs output is going to make photosynthesis less efficient than 3500k by causing some stress and the lack of red (main photosynthetic driver).

IIRC I believe a 3000k or 3500k cob has more blue than a typical MH bulb outputs.
Thank you for that explanation @skoomd ! Now I see what you were trying to tell me @Aolelon lol. So maybe a better plan is to use the (4) chilLeds for flowering. Then I’ll buy (4-5) 3500k COBs for Veg? Do you think this will be enough for 2 plants in a 2x4?
 

skoomd

Well-Known Member
Thank you for that explanation @skoomd ! Now I see what you were trying to tell me @Aolelon lol. So maybe a better plan is to use the (4) chilLeds for flowering. Then I’ll buy (4-5) 3500k COBs for Veg? Do you think this will be enough for 2 plants in a 2x4?
Good choice. And yeah, 4-5 cobs will be plenty for a 2x4 veg tent. I would use 4 cobs and drive them hard for 300-400w and run them high off the plants for better diffusion. My 320w samsung strips are 500PPFD 3 feet away so you could run them 3 feet away and have plenty of light for veg. The added diffusion will mean better canopy penetration and more efficient photosynthesis since the whole plant is getting even light instead of the canopy getting blasted.

But yeah, 3500k will make the plants much more manageable than 6500k, and they'll probably grow a good bit faster too. And you could use them as a flower light if you wanted to later on! The spectrum of an HPS bulb is what a 1750k-2000k COB puts off, so 3500k wont cause any where near the stretching you'd get from an HPS.
 

Odindris

Member
Ok, cool.. thanks a lot for the detailed info. If I decided to go with (5) 36v 3500k cobs, you think the HLG-240H-C1400B would be good?
 

skoomd

Well-Known Member
Ok, cool.. thanks a lot for the detailed info. If I decided to go with (5) 36v 3500k cobs, you think the HLG-240H-C1400B would be good?
Yeah that would be fine for a veg tent, but if you wanna be safe I would get an HLG-320H-C2100A and use 4 COBs so you have 320 watts to work with. That way you have plenty of headroom and if you wanna flower using it you'll be good. It doesnt cost much more than the 240h-c1400b but you'll get a lot more power. Since it's a veg light, efficiency isn't the most critical thing so driving the cobs at 2100mah will make things more cost effective.

5 cobs might not work off that driver btw, 5 cobs would be just about 180v and that driver you mentioned only can do 179v. So i'd just use 4 cobs to be sure. If the driver cant supply the voltage, it wont turn on the COBs.
 

Aolelon

Well-Known Member
Thank you for that explanation @skoomd ! Now I see what you were trying to tell me @Aolelon lol. So maybe a better plan is to use the (4) chilLeds for flowering. Then I’ll buy (4-5) 3500k COBs for Veg? Do you think this will be enough for 2 plants in a 2x4?
Sorry I should have explained it better.
I am currently using 3000k for veg and flower, but I think 3500k would be even better. Plus if you're using those ChilLeds for flower they should do the trick perfectly. Even in veg they should work just fine. The flowers would benefit from the 660nm more but it definitely wouldn't harm them in veg.
 

Aolelon

Well-Known Member
Yeah that would be fine for a veg tent, but if you wanna be safe I would get an HLG-320H-C2100A and use 4 COBs so you have 320 watts to work with. That way you have plenty of headroom and if you wanna flower using it you'll be good. It doesnt cost much more than the 240h-c1400b but you'll get a lot more power. Since it's a veg light, efficiency isn't the most critical thing so driving the cobs at 2100mah will make things more cost effective.

5 cobs might not work off that driver btw, 5 cobs would be just about 180v and that driver you mentioned only can do 179v. So i'd just use 4 cobs to be sure. If the driver cant supply the voltage, it wont turn on the COBs.
5 cobs would work off that driver. If they are the 3590s @ 1400mA they are only 34v which would be 170v. I'd have to look about the cmx22s
 

skoomd

Well-Known Member
5 cobs would work off that driver. If they are the 3590s @ 1400mA they are only 34v which would be 170v. I'd have to look about the cmx22s
Ah okay. Was just making sure. For a veg tent though, I'd rather save the money for the cob/heatsink and just use 4 instead of 5. Uniformity/efficiency isnt that important so you'll be saving money and getting nearly the same results.

And I agree, check out the cmx22s. Either those or i would use vero 29s.
 

skoomd

Well-Known Member
How many runs do you have vegging under 4000k cobs? Only reason I'm asking is because there is a vast majority of the grow world vegging under 4200k and growing monsters.
None personally. I am just judging by how veg is under 3000k and 3500k. Considering how much more blue 4000k has, it will grow very tight plants. My old blurple LEDs had less blue in them and my plants were VERY compact.




A 4200k CMH/MH doesnt have as much blue relative to the other wavelengths as a 4000k COB does. So a 4000k cob will grow more compact plants than a 4200k CMH would. A 3000k COB has about as much blue as a 4200k CMH does.
 

Kushash

Well-Known Member
Thanks Guys!
30 posts of enjoyable reading without any bickering.
How many runs do you have vegging under 4000k cobs? Only reason I'm asking is because there is a vast majority of the grow world vegging under 4200k and growing monsters.
And my post is in no way referencing your post. It's just enjoyable to read an LED conversation where a fight hasn't broken out, at least not yet LOL.
 

skoomd

Well-Known Member
And my post is in no way referencing your post. It's just enjoyable to read an LED conversation where a fight hasn't broken out, at least not yet LOL.
It's been nice now that that slinging-par guy seems to have disappeared. There's no need to have such heated bullshit debates. This hobby doesn't have a lot of solid knowledge that's backed by science, so there's always going to be disagreements over stuff. So it's better if we all butt heads together and share our own experiences and learn from each other than arguing over what is the "best" because what works for one person may not work for the next person.
 

Aolelon

Well-Known Member
It's been nice now that that slinging-par guy seems to have disappeared. There's no need to have such heated bullshit debates. This hobby doesn't have a lot of solid knowledge that's backed by science, so there's always going to be disagreements over stuff. So it's better if we all butt heads together and share our own experiences and learn from each other than arguing over what is the "best" because what works for one person may not work for the next person.
Lmao you know he's here somewhere, lurking under a different alias.
 

skoomd

Well-Known Member
Lmao you know he's here somewhere, lurking under a different alias.
Oh yeah for sure. I'm just glad he isnt posting anymore. Looks like a mod removed a bunch of his insane bullshit posts too. I wonder if the mods can IP ban him.
 

Kushash

Well-Known Member
I follow all the stuff going on. What I guess I wanted to say was as a reader it made it easier to follow the conversation and possibly learn something without the fighting. Usually the fighting takes over the thread and the conversation gets lost. :peace:
 

Odindris

Member
@Aolelon those clu048-1818 def do look good, and are cheaper than Cree. Might just have to go with those. Good spot.
This 2x4 is just a test DIY, as long as all goes well I should learn a lot, and translate that to a larger area. So really I don’t mind if I buy a couple extra cobs and run them lower. They’re going to be used in a few months anyways. I just want to get a really good grow here for my proof of concept.
Also appreciate everyone being really cool, and offering good advise.
 

Aolelon

Well-Known Member
No problem. When you decide what you're thinking on go ahead and post back here and we can help you with drivers ect..
 

Odindris

Member
So I’m gunna get (5) 3500k citizen clu048-1818 gen 6. As for the driver, I’m not really sure. I’m still trying to figuring that out. Also not really sure what wattage to run them at for optimal growth. Going with some 140mm pin heat sinks.
 
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