Is there a 4k version of these
I have those boards in m
Thanks for the informative link, I shared it to my friend and he is convinced a 4000k spectrum will be more suited for his autoflower goal, do you happen to have a match for a 3500 or 4000k light? If that is available, he will likely buy the needed components today
Do I also make a "simple" aluminum frame to hold the boards in the desired layout aswell as a mount for the power supply?
Just for pure curiously, can you not use more than 4 of these boards, perhaps 8, and put out alot more light and really rock a 3x3 or slightly bigger space? I like the simplicity of the boards that don't use heatsinks. Just curious
Sorry, I haven't been much help.
I've been running RTW for about 15 years; DWC and NFT prior to that. Pros of RTW are a little added insurance against pump failures and better buffering (cation exchange) of nutrients. Also deals with heat better as you don't have to control reservoir temps in summer nor worry about pythium root rot etc. RTW coco gives almost the same growth as DWC or NFT with some of the advantages of soil and other media grows (as above). You can also run organic-based nutrients if you're that way inclined (I am, and do).
I like the idea of 4xQB120s, but I went with the QB324s for a couple of reasons. Firstly, they have a mix of CRI 80 and 90 3000K Nichia LEDs that have a bit more red and deep red in them. The red end of the spectrum has proven itself for flowering and overall leaf/flower mass at the expense of slightly elongated nodes. We've actually found 4000K works well for veg for this reason. Initially we thought 5000K would work best - thinking along the lines of MH vs HPS spectra for veg - but found 4000K has enough blue to keep nodes tight and more red to promote leaf mass.
Those HLGs will over-drive, but IMO you want a minimum 320 driver for a 3x3 space. I run 2x 240s dialled down to 200W each in a 4x2 and it's about right (400W).
The QB324s are $139 with heatsinks at the moment. They bolt straight up to each other. You not only get 648 LEDs vs 480 with 4xQB120s, the QB324 LEDs are 6V/150mA Nichias vs 3V/200mA Samsung LM561Cs. The QB324s can be driven up to 250W each (500W total for $139) with active cooling of the heatsinks.
Pair this kit:
https://horticulturelightinggroup.com/collections/quantum-boards/products/qb324-with-slate-2-single-combo
With this driver:
https://www.arrow.com/en/products/hlg-320h-c1400a/mean-well-enterprises
Run them in series. You'll be able to crank them up to around 350-360W with no active cooling. Frames can be made out of a couple of lengths of aluminium L-frame, as per the photos I posted above.
Some bolt the drivers to the heatsinks, but I run all my drivers remotely to aid cooling the heatsinks and room/tent in summer.
You can do the maths on all the above. It will beat the hell out of a 400W HPS/MH. My experience is 400W of full-spectrum LED will yield similar to a 600W HPS horizontal grow (reflectors are not efficient; LEDs direct all their light downwards), so 350W may not beat a 600W HPS, but it will be close for less than 2/3 the power consumption, less heat, no new bulb purchases, and LEDs don't lose 10% of their light output after the first grow (and continue to deteriorate) like HID. The spectrum has a little bit more blue than HPS but it's not far off in the 600+nm range. It really only falls behind HPS in terms UVA/B output - I do think a small amount of UVA/B is beneficial for cannabinoid production.
Now, I'm only presenting you (and your friend) with options - and am happy to help (I'm far from an LED expert compared to others on this site) - but it's ultimately your decision. Nothing wrong with HPS at all, but for a 3x3 I'd want a 600W in there - and I'd want to keep it cool. Indeed, I'd be inclined to run it vertically with a floor fan blowing up . . . but that's another story.