Sir420 checking in with the rest of the LED fanatics here Im also into the DiY builds & have been studying for months now to be able to say I have a little understanding of building my own light! My priority is efficiency over everything. I think the most efficient light is to get lm301b strips from DIGIKEY and I am trying to create a 5x5 space light with 8-900 ppf at top of canopy. My frame will be almost wall to wall to spread even light & my GOAL is to make this fixture reach the highest ppfd with the lowest amount of watts possible. They say use 480 watts in 4x4 but I seen a guy pull over 2lb with only 364watts! ... So with the most efficient lights on the market (lm301b) can I make that 2lb with like 330-350 watts??
You can expect getting 1,5-2g/w depending on efficiency and the strain used!
30-35w per sft for regular and feminized plants, 20-25w/sft with automatics. If you see peeps claiming to get almost 1000g out of only 364w LED that's nonsense or just a lie. Maybe in 6-10 years or so...
With automatics you can already get pretty high g/w results cause you can work with pretty low intensities which makes photosynthesis more efficient but almost 3g per watt....? Sounds unbelievable... All over 1,7 is awesome!!!
LM301b is only the 2nd best Sammy diode, LM301h is already a bin better. Nichia's 757v3f1 are also better..
Sammy has released their new horti strip series (coolwhite + deepreds) but they are currently not available. Q- and H-inFlux series use LM301b and are available on digikey or arrow.com.
But if you look for the best one available LED-tech.de has 0,5m long LM301b strips with 98 fu....' diodes, 7s14p, 2,8A max current, 202lm/w at 700mA and still ~175lm/w at max. current. That means properly cooled you can get more than 50w out of a 20inch strip and you would get +9000lm!!! At 700mA the strips run with ~13-14w and +2800lm!
14,90€ per strip but the more you take the cheaper they get! And the best thing is the strips can be cut in 14 36mm long pieces, each module with 7 diodes in series and 200mA max. current. This means you can build almost everything with them, even a bulb form would be possible and all you need to drive them is a HLG or ELG CV/CC driver(A modell) with 20 or 24v no matter how short you cut them. Long and short pieces could all run in parallel on one and the same driver.
For a 4x 4' area you could use 30 strips running at 700mA each and the strips mounted on a 1x 1m alu-frame with 15 cross bars. That's around 400€ for the strips and up to 410w net.
As drivers I would use 2 HLG-185H-20A or 2 ELG-200-20A (both 10A nom., 11A max) and run 15 strips in parallel per driver. You would have up to 450w at the wall cause all HLG/ELG drivers are slightly under rated. 400-420w net. maybe and +80.000lm!
It's currently the most efficient LM301b strip and compared to Sammy's H-influx L06(2ft. strip/88 diodes) they cost almost half as much.
I've already 2 of them for testing and they work really well... So well that I already think about ordering more and using them vertically as side lights to build a kind of sun cloak. I've already thought about selling my current light(~2,5-2,6μMol/J system efficiency) to build something better, lol!
They must be soldered, but I like soldering! 
