picked up one of these (just to see if its enough to keep a small mother plant alive) ... ~US$3. There's a lot of variations and different styles/qualities/wattages/etc of this on ebay etc
It was marketed as 18W but it only draws 6W according to my power meter. Marketed as 500-800 lumen output depending on the seller. I get about 5000 lux from it @ 8" from my light meter. Haven't had the chance to properly test it apart from that though, and I'm not saying it's good or bad or other, just putting this info in case anyone else is curious.
28 diodes total (avg 0.21W each):
- 4 x white (seems to be Samsung LM561C's for these four?, guessing ~3K and ~6.5K)
- 1 x ultraviolet
- 1 x infrared
- 11 x red (630nm)
- 11 x blue (460nm)