I just measured my tank, and am surprised at the readings, and not sure where I should have things set.
About 6-8" below the water line, with my lights set to 50%, I am getting a reading of 80 on the PAR meter, per Chad, I multiply that number X5, then add 15%. This gives me a PAR of around 460. At the sand, I have around 150-175.
If I turn my lights to 100%, I get a reading of 95-100 about 6-8" down, giving me a reading of 575 PAR. The sandbed is about 240 or so.
Should I keep things at 50% with a reading of 460, or should I turn the up or down a little?