Saturday, January 17, 2009
LED Grow Lamp Evaluation
On January 7, 2009 two varieties of lettuce were started to compare the LED Grow Lamp to a Compact Fluorescent Grow Lamp for seed starting. The varieties are Brune D'Hiver and Gentilina, which have very similar growth patterns.
Both varieties were planted in rockwool cubes and received identical preconditioning and nutrients. A sixteen hour photoperiod was used for the compact fluoresent, and the seeds were placed in a humidity dome on a heating mat. The seeds under the LED grow lamp had a photoperiod of twenty hours, and were simply placed on a tray under ambient conditions.
As the photo above is labeled, the top row contains the seedlings grown under the compact fluorescent, and the bottom row contains the seedlings grown under the Red/Blue LED grow lamp.
For further consideration I would like to point out that the compact fluorescent is rated at 125 watts, and the Red/Blue LED grow lamp is rated at 13.5 watts. If my math is correct, that is a difference of almost ninety percent in energy consumption!
Aside from the energy cost; the compact fluorescent fixture and bulb, which only lasts a year, would be about $150. The small LED grow lamp, which has a life of fifteen years, cost me slightly more than $34, including shipping.
The seedlings grown under the Red/Blue LED grow lamp are further advanced, and are darker green in color.
Well, at least in terms of seed propagation, I am now a believer. I was impressed to the point that I have ordered a 90 watt LED UFO grow lamp for indoor growing and supplemental lighting for the greenhouse. The 90 watt LED is equivalent to a 400 or 600 HPS, and covers a growing area of 12 square feet. Additional advantages are that you do not have to change bulbs for the growing and flowering cycles, there is no ballast or ventilation to deal with, and it has a life span of more than 60,000 hours. Basically, it is a no-brainer.