Quote Originally Posted by stinkyattic
Actually mercury (Hg) lights are no good either.


Plants need more in the blue for veg (metal halide) and more in the red for flower (Sodium).

Read up on the appropriate flourescent types that approximate these wavelengths.

Halogen, incandescent (even plant lights), uv (black) lights, heat lamps, propane lanterns (yes it has been suggested on this forum), and mercury vapor lights are not useful to plants. You want something in the right range that does not emit too much heat or use too much juice. The only promising new technology is LEDs just because you can really tweak the wavelength by adding different types to your growing array.

Why reinvent the wheel?
mercuries work just fine, just less efficient. AND Halogens work too, they'll just burn down your house.
http://boards.cannabis.com/showthread.php?t=67935
4x5 Reviewed by 4x5 on . halogen lighting is it worth it or should i flip green till i can get a highpressure Sodium? Rating: 5