I'll take that ^^ bet
.........don't forget Hans has been growing cannabis with leds longer than any of us by years. He built his panels to be one of the most efficient per watt consumed. most of the burden fell on the cree XP-e 630 nm, which by todays standards its still one if the best umol/joule.
NOTHING on the market can cover a 4x4 flower area with 260watts for a thousand dollars shipped.
Dutch grower got 365 grams dry with that setup......I know of zero 250w hps grows getting those #s without a light mover.
their is a reason why he won't use a primarily"white"spectrum, he still does allot of R&D btw.......
Growers want Results not theories......that's why people love hid.