Ceramic Discharge Metal Halide lamps (sometimes just called Ceramic metal halide, or CMH) have been used for many years for their great light output and spectrum. They are ideal for applications where natural light is desirable like outdoor lighting and car showrooms.

In more recent years, they have begun to be used as plant grow lights. There are many advantages to using CDM/CMHs as grow lights. Due to their full spectrum light output, they offer fantastic plant health, fast growth and superb crop quality. Compared to HPS, the blue in the spectrum of CDMs reduces the length of the internodes and reduces vertical stretch. The 3K contains lots of red for great yields when used as a standalone light.

When it is used in combination with HPS lights, far-red output of the CDM will greatly increase crop quality by encouraging greater essential oil production and flavour in the end product.