High Pressure Sodium, Metal Halide, and LED (light emitting diode, think back to “Lite-Brite”)
Very nice break down of the lights,
credit goes to DatDank
As he points out the heat is easily less, and allows for less electricity consumption, they will last you longer over time, but you end up paying more up front, but hey, why not. Its not like i want to bother with balasts and or changing bulbs ..and more expensive bills ya know, if i was in the growers shoes those are things i’d consider before taking the plunge!