There is a common misconception with single-chip LEDs that "Bigger is better", however this is precisely the opposite of the truth. As with all things electrical, the more current you drive through an object the hotter it will become, and with LEDs the #1 cause of failure and premature degradation is heat. While LED manufacturers around the world are working to improve the thermal handling of 5W LEDs, they are presently incapable of matching the efficiency of 3W models.
Twice a year Hydro Grow executives purchase the best 3W and 5W LEDs from leading LED manufacturers to test and document the achievements made by these companies. Of the companies on the market selling LED Grow Lights built with 5W LEDs, many of the more expensive models are using Osram LEDs. On the most recent test in February 2012, 4 different Osram LEDs were compared against another on the same test equipment used for all Hydro Grow testing. All LEDs were of the highest BIN and the highest quality offered by Osram; however the 3W models outperformed their 5W counterparts by a significant margin.
The 3W LEDs averaged 14% more light output with 33% less power consumed compared to the 5W models from the same company. While these results do not speak for all 3W and 5W comparisons, Hydro Grow has found time after time that the most efficient 5W LED can be matched in output by a competing 3W at 33% less power consumption. Companies selling LED Grow Lights with 5W LEDs are preying on the uneducated consumer who doesn't realize that more power consumed doesn't equate to more light output with 5W LED Grow Lights. It is for this reason Hydro Grow uses 3W LEDs in all X-PRO LED Grow Lights to ensure the highest output with the least power consumed.