Square reflectors give a more concentrated beam. More intensity in the center, less at perimeter. Parabolic ones gives an evenly light distribution. So the election depends of grow space geometry and the bulb power.

You can download ligting 3D simulators in lighting webs (as Osram or Phillips), so you can simulate the lighting accurately on both reflectors, in order to choose. Think that areas below 10000lux of HPS arnt productive, and what 100000lux is more than your plants can process, so look for the larger area over 25000lux, and preferably over 40000lux.
knna Reviewed by knna on . Different HPS reflectors? question. So i've noticed two main types of reflectors...the rectangular and the parabolic. are the parabolic worse? what if i coat the room in reflective material? will it be a big difference in quality? Rating: 5