Review on CHANZON 10 Pcs High Power Led Chip 4W RGBW 8 Pins (300MA - 350MA For Each Color 4 Watt) Multicolor Super Bright Intensity SMD COB Light Emitter Components Diode 4 W Bulb Lamp Beads DIY Lighting by David May

Worked better than I expected. I wired two of these full spectrum cobs in parallel to a old USB cable, a small buck converter to drop the voltage, and used some thermal adhesive paste to sloppily glob them to an old heat sink I had laying around. This was just for a quick test. after one week I was so impressed with the results I decided to leave this test setup as a permanent light. The water sprite in the picture grew from 1/4" cutting to 5-6" growth in just over a week.