The Controversy Surrounding LED Grow Lights

Anytime a new product is introduced on the market, there can be a bit of controversy surrounding it based on whether it actually works as marketed. Such is the case with LED grow lights. Although there has been some disagreement over how well the bulbs work for growing plants indoors, research indicates that the controversy is not founded.

Some have speculated that one of the benefits of LED grow lights may also be a drawback: case in point is the fact that LED grow lights run very cool and produce very little excess heat, unlike other lamps such as HPS lights and MH lights. It has been said that plants grow more leggy under LED grow lights than other grow lamps such as HPS lights. Light is not the only item that plants need for proper growth. Bottom heat is needed to get seeds to germinate, and warm conditions are usually optimal for fast plant growth. Since other grow lights such as 1000 HPS lights put off more heat, it can contribute to warmer growing conditions. This may mean that a heat source might be needed for use with LED grow lamps to bring on equal growth results.1

Another area that some claim as controversial is that additional blue spectrum is needed for stocky stem growth in plants than is given by LED lights. NASA has performed some testing by its Astroculture Flight Unit, where they determined that LED lamps with eighty percent red spectrum and twenty percent blue spectrum produced better growth than HPS lights and other HID lights, yet neither produced better growth than sunlight.2 If you want to boost the bloom cycle, you may choose to add additional blue spectrum LED lights to mimic summer sunlight and the resultant productivity of plants in response. Some of the latest LEDs also allow you to adjust the amount of each spectrum, so you can adjust them for optimal plant growth.

There are many benefits from LED lights. They require less equipment to operate than both HPS lights and MH lights. Unlike these traditional lamps, the LED needs no ballast, fans or reflectors to operate at optimal levels. LED bulbs also last longer, up to five to eight years longer than HPS lights.

HPS lights are also a good choice for plant lighting. Although they run hot and do not last as long as LEDs, they also have a lower initial cost than many LED lights, and come in blue, red and full color spectrums.

It has been suggested that perhaps a combination of both LED and 1000 HPS lights could produce optimal results. The 1000 HPS lights would bring heat as a byproduct of the lighting, warming the growing space without the need for the additional purchase of heaters. The LEDs can add additional blue light as needed.3

1, 3 Led4growth's Blog. Retrieved on May 15, 2009.

2 Wisconsin Center for Space Automation & Robotics, STS-57 Endeavour, 21 June 1993-01 July 1993. Retrieved on 5/15/09.

From years of indoor and hydroponic gardening, Susan Slobac has developed an in-depth knowledge of led grow lights and writes frequently on the subject.