Correlated Color Temperature (CCT)

Correlated Color Temperature (CCT) is not how hot a lamp is. Color temperature is the relative whiteness of a piece of tungsten steel heated to that temperature in degrees Kelvin (K). HPS has a warm (red) color temperature of around 2700K as compared to MH at 4200K, which has a cool (blue) color temperature. This value is largely irrelevant to plants.