Great, thanks for the clarification Feenix!
So 165 watts draw for 6 plants- that's good compared to 3-4 plants under my 210 watts of LED.
2 of these COBS would nicely power a 60x60cm tent using half the electricity. 3 of them would allow me to "spotlight" some of the lower growth.
That's what I figured about the calmag.
I would love to get rid of the fan noise- how hot do they get?