There has been a lot of confusion about the switch from MH to LED and all of the different ways to measure the light output and power. This is a good reference......
How to Choose and Compare LEDs - They're Not Metal Halides! - Captive Aquatics: An Aquarium and Ecology Blog
How to Choose and Compare LEDs - They're Not Metal Halides! - Captive Aquatics: An Aquarium and Ecology Blog