What max power to use - Reefbreeders Photon 48 in 90 gallon mixed reef

We are running a Reefbreeders Photon 48 fixture in a mixed reef 90 gallon that has a little bit of everything. SPS, LPS, soft squishy things, polyp things, etc.

What would you recommend as a maximum power to run for about an hour per day, with a steady increase and decrease in power as the day goes on? Currently the light has no optics, is 3.5 inches above the water level (Our canopy restricts height), and the water depth is 20 inches to the sand bed. We do have a lobo brain on the sand bed, and wouldn't mind putting a clam down there as well. Our current max power for an hour per day is 55 for whites and blues as we have acclimated the light to the tank. No bleaching or adverse reactions to the light thankfully, and I feel we are getting close to our max on what our optimum power curve should be.

Any ideas?

 

Good questions, will be following...

 

im running a photon 24 120 optics on my 57g 9'' above water, 21'' tall tank...my maxes are 75% both channels for 3.5 hours per day..... I have mixed reef with lps sps crocea clam and 2 rbta's havent had any issues. light has been running since july...I started at 35% both channels and bumped up 5% a week until I hit 75%, I havent considered bumping it up further due to everything looking good and didnt want to risk bleaching