Building a 12-COB Citizen fixture for my first grow, help!

trick2grows

Member
Hey guys!


I've spent the last few weeks trying to learn from the pros (GreenGene, Growmau5) and educate myself about LED's so I can have a decent shot at a nice DIY system. I've spent hours watching youtubes and reading but the amount of information available is monumental and there always seems to be another factor I’m not familiar with. Plus my electrical and engineering knowledge is pretty subpar (to put it lightly). If you need taxes prepared or your nails done hmu, but I've never even held a handsaw or a drill, so I'm struggling.



I've ordered some parts, but I still have room in my budget to wiggle around and maybe change a few things if I need to. I plan on building a 12-cob fixture, with inspiration from some Growmau5 videos.



Here's what I've got going so far:



12x Citizen CLU-048 1212 90CRI 3500k cobs

(I also bought 6x the 80CRI[after I learned what CRI meant] 5000k cobs. I was debating running six 3500's and six 5000's—input?.)

12x 120nm anodized aluminum pin heat sinks from Cobkits. I'm not certain on the dimensions of them but they were recommended with the CLU-048's and I plan on running my COB's pretty soft, at 700ma so I'm sure they're adequate).

2x HLG-120H-C700-A Meanwell drivers

12x Ideal COB-holders

12x Ideal reflector adapters

12x Angelina reflectors

14 gauge solid-core wire (the two stores I visited didn’t sell 16 or 18).

Enough angled aluminum to finish the build, plus some extra.

I plan on building three bars with four cobs on each, and running them at 700ma. I’m operating with a 4x4 tent.



Some questions I have are:



Is the 14-guage wire overkill? Should I purchase some 16 or 18 online?

Should I alternate the 3500k and 5000k COBs? I just placed my order an hour or two ago, so I’m sure I could change it if the 5000k’s aren’t useful or good for the grow.

How far apart should my bars be spaced? I’m not talking about the cobs on the bars, I’ve got those set at 8 inches apart.

And lastly, but most importantly, will I be providing enough illumination for my space? I know 700ma is quite soft. Will it be too dim? I don’t mean to be lazy, but I kind of feel like I’m drowning in all these calculations and new terms like micromoles and joules. What should I be shooting for in regards to micromoles per square foot?



Thanks in advance for any help—I’m super grateful.
 

Danielson999

Well-Known Member
Depending on what you're growing, 300w or so in a 4'x4' might be fairly weak. People are typically using 600w to grow MJ in a 4'x4' with cobs, a few people are using even more than that. At the very least I would add one more bar of 4 cobs to that to bump it up to 450w approximately but you could also just drive the 12 cobs you already have harder. 3 meanwell HGL-185H-xxxx sounds better.
 

linky

Well-Known Member
This going to be used for flower or both veg and flower? If for flower only I would stick to 3000k and or 3500k cobs, 4000-5000k is ideal for vegging only. As Danielson mentioned I would run them at 50 watts each to give you 600 watts total, would make a fantastic flowering light for a 4 x 4.
 

trick2grows

Member
Well, for my first grow it'll be for both. I planned on investing the dividends in to a second tent, one for veg, one for flower.

Thanks for the advice on where to slap the 4-5k's!

The only question remaining then is if the driver I suggested (185-H C1400) would fit my cobs at 1400ma. (3 of them haha)
 

linky

Well-Known Member
You can run 4 cree 36v cxb 3590s off a hlgh-c1400B no problem, I have 2 12 cxb3590 cob fixtures running off those drivers. So I assume you could do the same for the citizen 36v cobs. The mean well 185 is slightly underrated, it will do 200 watts.
 

Jeeyah

Well-Known Member
I would run about 400 watts or so in that space. I use 350ma-700mA in veg. 1400-1750 works great in bloom.

The setup you designed would be very efficient though. It would work absolutely fine. You're doing more COBs close together.
 

CobKits

Well-Known Member
14 ga wont work with any holder. 18 solid is recommended (even that is slightly out of spec on some holders on size but proven to work well with both bjbs and ideals)
 
Last edited:

Jeeyah

Well-Known Member
Use the 3500K for bloom. 5000K for veg.

If you need to get quick electronic parts, wire, etc. Advance Auto Parts has wire and connectors and stuff.
 

VegasWinner

Well-Known Member
Hey guys!


I've spent the last few weeks trying to learn from the pros (GreenGene, Growmau5) and educate myself about LED's so I can have a decent shot at a nice DIY system. I've spent hours watching youtubes and reading but the amount of information available is monumental and there always seems to be another factor I’m not familiar with. Plus my electrical and engineering knowledge is pretty subpar (to put it lightly). If you need taxes prepared or your nails done hmu, but I've never even held a handsaw or a drill, so I'm struggling.



I've ordered some parts, but I still have room in my budget to wiggle around and maybe change a few things if I need to. I plan on building a 12-cob fixture, with inspiration from some Growmau5 videos.



Here's what I've got going so far:



12x Citizen CLU-048 1212 90CRI 3500k cobs

(I also bought 6x the 80CRI[after I learned what CRI meant] 5000k cobs. I was debating running six 3500's and six 5000's—input?.)

12x 120nm anodized aluminum pin heat sinks from Cobkits. I'm not certain on the dimensions of them but they were recommended with the CLU-048's and I plan on running my COB's pretty soft, at 700ma so I'm sure they're adequate).

2x HLG-120H-C700-A Meanwell drivers

12x Ideal COB-holders

12x Ideal reflector adapters

12x Angelina reflectors

14 gauge solid-core wire (the two stores I visited didn’t sell 16 or 18).

Enough angled aluminum to finish the build, plus some extra.

I plan on building three bars with four cobs on each, and running them at 700ma. I’m operating with a 4x4 tent.



Some questions I have are:



Is the 14-guage wire overkill? Should I purchase some 16 or 18 online?

Should I alternate the 3500k and 5000k COBs? I just placed my order an hour or two ago, so I’m sure I could change it if the 5000k’s aren’t useful or good for the grow.

How far apart should my bars be spaced? I’m not talking about the cobs on the bars, I’ve got those set at 8 inches apart.

And lastly, but most importantly, will I be providing enough illumination for my space? I know 700ma is quite soft. Will it be too dim? I don’t mean to be lazy, but I kind of feel like I’m drowning in all these calculations and new terms like micromoles and joules. What should I be shooting for in regards to micromoles per square foot?



Thanks in advance for any help—I’m super grateful.
18 gauge wire for most applications, solid is not necessary. for extension if you rem0te mount your drivers you cna use two conductor 18 gauge security cable. If you want you cna use solid for your cob connections, no big deal easy to insert harder to solder. The 90 cri has more red and the 80 cri has more blue from what I have read. More red is better for bloom and blue beter for veg, together they are killer. great setup looks like you made a good choice running them at lower amps 700mA is always better.
 

trick2grows

Member
Just wanted to pop by and say thanks to everyone who helped...

I had to put off my project for a few months due to some IRL issues, but... She's built. And she's a beast. One of my best friends moved next door a few months ago, he's an electrical engineer. I lugged my beast over to his house and I cringed while he plugged it in. SHE WORKS. I didn't fry anything. No one blew up. Please ignore my laundry pile and the wires I still need to zip down.

Time to get growing. : D
 

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