you have answered your own question.....this is why LED's are more efficient with more than 80% of the light used by the plant and HPS only about 20 - 30 % of the light absorbed is actually used...this is why less wattage can match production of HPS...LED's hit the main lighting wavelenghts with little energy wasted:smokin:

not to mention the energy for cooling costs...thats why it takes 1000w HPS to get good results!:thumbsup: