Well for starters, return that light if you still can. It's crap.
If you are stuck with it, you need to know that in no way will it replace even one 1kW HPS. I wouldn't expect it to cover more than about 12 square feet during flower. I looked it up on amazon and it draws 480 watts. To truly replace a 1kW HPS with LED (quality LED) we need about 35 watts per sqft, and thats with quality LED.
If I was stuck with that light source I would be stunned it I managed to get 1.5 pounds off it. If you hit a pound with it, pat yourself on the back and use the money to buy a better light.