true HPS grow lamp, not high lumen output sodium lamp. with right lumen, right PAR, right spectrum for hydroponic. Different crops need different spectrum, ... report like below:Very good result!!! isn't it? 400W with 60030lm output, that's true, it was tested ... for plant growth.Why? Because of spectrum. This lamp called high lumen output HPS, red and blue lights are less than grow light, green light ...