A few questions before I build my first CXB3590 lamp

Greetings,

First post here from a long time lurker. I'm planning my first LED build where I’m covering an area of 1.2 x 0.45 metres = 0.54 sq m (approx 3.9 x 1.5 ft = 5.8 sq ft). I'm thinking of getting 4 x CREE CXB3590 72V and put them on a single MW HLG-185H-C700(B). For cooling I think I will use either 4 x ARCTIC Alpine 11 Plus or Alpine 64 Plus. This setup should give me 101 PAR watts, so that would be 17.5 PAR W per sq ft, which I guess is sufficient? I've asked Jerry from Kingbrite for prices on COBs and drivers.

I have a few doubts I was hoping you could help me clarify:

1) Kingbrite has the CXB3590 3000k, 3500k, 5000k, and 6500k in stock. I had originally planned on using 3500k for both veg and flower, but I was wondering if it would be worth the extra cost getting an additional 4 x CXB3590, and then go for 5000k or 6500k for veg and switch to 3000k or 3500k for flower?

2) If using different colour temps for veg and flower would you suggest 5000k or 6500k for veg and 3000k or 3500k for flower?

3) In case I go for two different colour temperatures can I then simply change the COBs mounted on the coolers using the Ideal 50-2303CR holders when I’m switching from veg to flower?

4) Another concern is bin codes, which I haven't fully understood yet. Kingbrite has the CXB3590 3000k (CB), 3500k (CD), 5000k (CD), and 6500k (DB) in stock. Are there any differences in quality between these bins, i.e. is one bin code better than the other?

5) Lastly, what do you think of my proposed setup? Anything I should change?

Thanks for the help.

Besides switching out buttered cobs which would be a pain in the butt, my experience is the lower K cobs veg fine. Plant growth is robust and time to flip is well within standard time frames. With this in mind, what's the point in using higher K lamps for veg? They will be a tad more efficient but that probably isn't going to justify manually changing out cobs. Some people (me included) have built dual K lamps with a switch, but I no longer feel the need to design a lamp around the concept. Personally I would pick 3000K and grow with it.

Thanks for the input Rahz. I thought higher 5000k or 6500k lamps would give the plant more strength and prevent stretching in veg compared to e.g. 3000k or 3500k. But if it doesn't make a big difference I will use just one colour temperature for the whole grow. It makes everything so much easier – and cheaper

What about those bin codes? I'm buying from Kingbrite so my choices are CXB3590 3000k (CB) or 3500k (CD). Ignoring the colour temperature is CB better than CD? Or am I misunderstanding the way bin codes work?

CD is better than CB as far as lumens go. Concerning plants it's a bit more complicated. The 3500K will be a tad more efficient but how the spectral output translates into plant growth... I personally would go with 3000K CXB but many others would pick the 3500. For me, as long as there's enough blue to support veg I want the lowest K possible. For Cree this means 3000K. For Bridgelux Vero v2 this means 3500K.

I don't think you can go wrong either way though.

Bonjour
Like Rahz said I choose 3500ºk because CD is a higher bin...but 3000º will work as fine...
Aim for 30w sq/ft...so 6 x30=180w...so 200w of your hlg-185-1400b will work fine (cxb 36V)
And for vegg 15/20w sq/ft...so 90/120w...of 5000ºk is enough...maybe a few V18...cheaper and good enough for a good vegg...
Have a great day ★

Thanks for clearing that up about the bin codes. Really appreciated!

Bonjour Lj, thanks for chimming in! 4 x CXB3590 72V x 0.7A would give me just over 200 W (and approx 101 PAR W). So that should be just perfect if you suggest 30W/sq ft, right? Any reason you suggest 36V and 1.4A instead of 72V and 0.7A?

Rahz said:

Besides switching out buttered cobs which would be a pain in the butt, my experience is the lower K cobs veg fine. Plant growth is robust and time to flip is well within standard time frames. With this in mind, what's the point in using higher K lamps for veg? They will be a tad more efficient but that probably isn't going to justify manually changing out cobs. Some people (me included) have built dual K lamps with a switch, but I no longer feel the need to design a lamp around the concept. Personally I would pick 3000K and grow with it.

Click to expand...

I'd add that I'm planning a setup with CXB3590 and I'm planning to use the 3500k CD bin chip for everything. I leaned towards this choice because the chip is slightly more efficient and many others here have had rave worthy results with the exact same setup. My 860W CDM lamps run at about this same color temperature- which helps my comfort level.

Bonjour
REALSTYLE said he only use 3500ºk from start to finish...and he have very good results...so I am going to give it a try too!
But when I saw how a 3500ºk can vegg...5000ºk must be awesome...
Is anyone tried both? 3500ºk and 5000ºk for vegg! Is there a huge difference since 3500ºk vegg well?!
Have a great day ★

And I choose 36V over 72V because I believe that in the future I am going to run them lower and lower (for efficiency and because I am going to upgrade everything little by little...and because technology change fast I believe I would buy better one when they will be available...cxc??? 4070???...who know?!) So with 36v it will be easier to source a good 350mA driver to run them at 12/13w...harder to find a 175mA one...
Anticipation...!
CU

A few photos from yesterday 1/2

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