, with a 525 gallon reef you obviously have a respectable budget. I would pick up an Apogee PAR meter (Model QMSW-SS about $300) and actually test what your lights are doing for you now and go from there. The unit has a sensor that can be submerged.
Pricey, somewhat, but if you think about it you can get detailed information how to choose the best wattage for your tank and also the best time to change bulbs, etc. I think it is a value that could pay for itself with a reef the size of yours or at least give you peace of mind.
My own opinion, I think 250w would do you fine with your SPS
in the upper 3/4 of the tank (regarding what lighting they prefer, not all SPS
are the same) and the lights spread out with the proper 2'x2' coverage area.