The naked eye can be very deceiving. Grow lights that still seem bright enough to us are gradually losing their power, reducing their effectiveness and leaving your plants less vigorous than they could be.
Fluorescent bulbs – including standard and compact types – need to be replaced every six months, as the gas inside diminishes. Newer, more powerful T5 fluorescents hold their power for up to a year. High-intensity lights, such as metal halide and high-pressure sodium, burn hot and need to replaced after six to 10 months of use. LED lights can be more costly than other types of lights, but they last for up to three years or more.
No matter what type of grow light you use, they tend to gather dust and grime, which reduces their brightness. Be sure to wipe them clean before every grow cycle.
