I preffer medium to high lighting ,if we are going to use par readings to determine the level preffered are we speaking at the bottom outer edge of the tank ?? I try to set all our tanks up at 200 to 300 par at the bottom of the tank.When decieding your lighting tho it's best to know what you want in the tank?? for example if I want chalices in the tank I would like a 150 par max at the bottom and would like around 250 in the midzone.If I am going sps I would strive for 300 on the bottom and around 450 in the midzone. Just my .02 tho