Grow Light Comparison Chart

Grow Light Used Watts Growing Area Heat Output Recommended Light Height Above Plants Bulb Life

(hours)

Primary Secondary

Incandescent 150 0.5' x 0.5' 1' x 1' Medium 1' to 2' 2,000

CFL 40 1' x 1' 2' x 2' Very Low 3" to 1.5' 10,000

CFL 125 2' x 2' 3' x 3' Low 6" to 2' 10,000

CFL 200 2.5' x 2.5' 4' x 4' Low 6" to 2' 10,000

2' T5 (single) 24 1' x 2' 1.5' x 2.5' Very Low 3" to 2' 20,000

2' T5 (2 bulbs) 48 1.5' x 2.5' 2' x 3' Very Low 3" to 2' 20,000

2' T5 (4 bulbs) 96 2' x 3' 3' x 4' Low 6" to 2' 20,000

4' T5 (single) 54 1' x 4' 1.5' x 5' Very Low 3" to 2' 20,000

4' T5 (4 bulbs) 216 2.5' x 5' 4' x 6' Low 6" to 3' 20,000

4' T5 (8 bulbs) 432 4' x 6' 6' x 7' Low 1' to 3' 20,000

HPS 250 3' x 3' 5' x 5' Medium 2' to 3' 24,000

HPS 400 5' x 5' 8' x 8' High 3' to 4' 24,000

HPS 600 6' x 6' 10' x 10' High 3' to 4' 24,000

HPS 1000 8' x 8' 12' x 12' Very High 4' to 6' 24,000

MH 250 3' x 3' 5' x 5' Medium 2' to 3' 10,000

MH 400 5' x 5' 8' x 8' High 3' to 4' 10,000

MH 1000 8' x 8' 12' x 12' Very High 4' to 6' 10,000

Growing Area

The growing areas listed above assume the light bulbs are being used in a fixture

with a reflector.

Primary - Use the area in this column if the grow light will be the main or only source of light for the plants. This includes areas where minimal light comes from windows or standard house/office lights. Use the area in this column if the grow light will be the main or only source of light for the plants. This includes areas where minimal light comesfrom windows or standard house/office lights.

Secondary - Use the area in this column if the grow light will be used in a greenhouse or other area that receives direct sunlight for part of the day to supplement the light from the sun.

Heat Output

The chart above uses a combination of the light bulb temperature and the dimensions of the bulb(s).

Bulb Average Bulb Temperature . Bulb Average Bulb Temperature

T5 100 to 120° F Incandescent 220 to 260° F

CFL 130 to 180° F MH/HPS 450 to 550° F

How Long Should Grow Lights Run?

This depends on the type of plant. Foliage plants need about 14-16 hours of light per day. Flowering plants need 12-16 hours of light per day. You should give most plants at least 8 hours of total darkness daily. Try to have the lights on at the same time every day. You can get an automatic timer for your lights to make it easier.

The Electrical Cost to Run a Grow Light System