Hello everybody. I need help with figuring out how high to mount a T5 fixture. It’s a six bulb 60 inch t5 fixture. I have them mounted in an open canopy about 16 1/2 inches above surface of water. I used my par meter and measured the bottom of the tank and it is around 240. I want it to be lower, but it also doesn’t make sense to me how I could be so high up and yet still have such a high reading 2 feet beneath the water. Can anybody relate or give me some info about what I’m doing wrong? I am running four ATI blue pluses, one coral plus and one true actinic. It seems like every time ive raised up the lights I’m only losing about five par at a time. It doesn’t seem like I should have to be this high up and still be so high in par.