Types of Grow Lights

There are several types of grow lights, some of which are better than others, based on electrical efficiency, light spectrum output, light intensity output (lumens) and cost. These include fluorescent, metal halide, high pressure sodium, and mercury vapor, but should not include regular incandescent lights, which are not acceptable for growing.

Fluorescent Lights

Fluorescent lights are inexpensive, accessible and tend to be small, giving you the option to pack more light into a small area. The "cool white" spectrum option tends to be good for vegetative stages of growth, while the "warm white" spectrum is better for flowering stages of plant growth.

Metal Halide

There are two types of HID (High Intensity Discharge) lighting systems, one of which is metal halide. Metal halide lights are good for use in the growing phases of plant growth and typically give out more blue spectrum light, which is good for vegetative growth.

High Pressure Sodium

High pressure sodium (HPS) lights are arguably the best indoor growing lights. They are expensive but emit lots of orange, yellow, and red spectrum light, which is excellent for flowering stages of plants. HPS lights emit high levels of lumens and are the most energy efficient type of grow lights.

Mercury Vapor (MV)

Mercury vapor lights are not the most efficient for growing, even though they are popular. They use more energy than metal halide and give out less lumens of inferior spectrum.

Warning

Extreme caution is necessary when setting up an HID lighting system. Faulty wiring schemes greatly increase the risk of fire.

References

• Home Harvest: Indoor Plant Grow Light
• ACF Indoor Plant Grow Lights