I've read a lot of people on here using LED lights but no mention of COB lights. I put one of these together last year and it was fantastic. I was over wintering about 8 plants on it and they continued to produce under it, until aphids wrecked the plants. If I recall the specs right it was a 2700k light, 36v, they can produce about 16,000 lumens but I had mine set for about 12,000. Cheap to run too. Anyone else tried these? I think I spent $75ish putting it together.