There are three main determinations for how much "power" an led will put out (avoiding lumens as that's a measure of how we perceive the light and even avoiding par as it includes everything between 400nm and 700nm even though a good chunk of the green spectrum is never used for photosynthesis), and they are: wattage of the led, the amperage the led is being driven at, and the optics used. All the documentation I've read lists decent optics, weak wattage, and no info. on what its being driven at... That being said, after looking at their charts I'd shy away from them if you want a heavy sps tank, but it should work fine for most softies and certain lps's.