My 4 bulb 48" cheap hydroponic unit will easily hit 130-135 at 24" if Im running all 6500Ks for example. It has individual reflectors which are good, but not great. Your WP probably has better.
I run 3 out of 4 red/pink bulbs which brings the PAR down into the 110 range. The ZM Ultra is a higher PAR bulb than the Flora. Im currently using both.
Not sure if there is much difference directly underneath between a 48" and a 36" unit. My guess would be not much.
So like I said just guessing, can probably count on having at least 90-ish though
Last edited by burr740; 01-25-2016 at 12:28 AM.