High pressure sodium lighting will emit about the same amount of light as metal halide lighting, but it will not generate as much heat as they do. They also produce light that is mostly in the orange and red spectrum, and this is what the cannabis plants use the most when flowering.

Combining lighting is what many growers do for the optimum growth for their marijuana crops, using fluorescent lighting during the seedling stage and when starting clones. Then use the metal halide lighting during the vegative growth stage and during the flowering stage employ the use of high pressure sodium lighting.