New Project: LED Lighting Experiment

I've finally gotten tired of trying to find good information online about growing under LED lights. Forums are noisy with people who just aren't very helpful- skeptics and underinformed growers, along with various vendors trying to skew the data. Vendors who sell LED's claim that they're the next great thing and vendors who sell conventional HID lighting dismiss LED lighting altogether.

Also, there are paralyzing choices of LED grow lighting devices on the market. The "UFO" type seems to be really popular, but expensive. There are other high-end choices costing $1,000 or more. At the lower end of the market are cheap imported devices, some of which are well-built, others whose LEDs are so overdriven (to achieve greater brightness) that one of the LED's most favorable features- their long life, is greatly reduced.

I finally decided that the best way to figure out how LED's might affect my growing would be to try a couple of small experiments. I located some mid-range, mid-priced LED panels and set up a simple experiment with lettuce plants:

Here I have a 15 watt panel with 225 blue LED's suspended over a small growing container. My growing container is a small 3-quart Gladware container with five 2-inch holes cut in the lid. In each hole I have a 2-inch net pot, and in each net pot I have a Rapid Rooter plug with three lettuce seeds.

In the center pot I have planted Bullet romaine lettuce. In each of the four outside pots I have planted Tom Thumb butter leaf lettuce. I selected lettuce plants for this experiment because lettuce isn't very picky. It grows quickly, uses a very simple nutrient solution and doesn't require any support for fruiting or flowering, only vegetative growth.

Light in the blue spectrum is largely used by plants for vegetative growth. I am concerned with the total lack of red light in this setup, but I intentionally designed this first experiment to test blue-light only on vegetative growth in lettuce.

Based on the results of this experiment, I will probably try growing lettuce side-by-side under blue-only, red-only, and red-blue LED panels to determine which is the best mix of LED color to grow lettuce under. Conventional wisdom supports that the red-blue mix will be best, but I will be thorough.

Once I identify the most effective LED grow lighting setup and have a chance to assess the results, I'll arrange an LED-Compact Fluorescent growdown(tm) to see if low-power, low-cost LEDs can meet or exceed my proven results under 125 watt CF lighting.