Quote Originally Posted by demoreal
Has anyone done a side by side with an MH and HPS for flower? Does the MH create more leafy growth?
MH does promote more leafy growth, hence it's used for veg, and the red of an HPS mimics the fall (harvest) sun.

i have read a study, and although it doesn't relate to MH vs. HPS specifically, it is still interesting. two crops of MJ were grown, one at 4500ft elevation, the other at 9000ft. the crop at 4500ft had about 25% more yield, but the one at 9000ft had better trich production. i know this pertains more to UV than spectrum (although, UV is a spectrum, or a group of really). with that being said, blue light and light closer to the blue end of the spectrum is more powerful than light at the red end due to frequency (i believe).

good growing!


-shake