Lighting is one of those things that people struggle with, especially if you don't have access to a PAR meter. Even with a PAR meter, it can still cause problems. Case in point, I got some frags in last week and placed them on a new frag rack I had just installed at the rear of my frag tank, high up on the glass. One of the frags RTN'd and stripped after 2 days and I assumed I had over lit it too quickly. I had a similar frag on the same rack from a different order and vendor, so I quickly moved it down to the old, lower rack to prevent it from suffering the same fate.
As I am soon to be picking up a HW frag that cost more than other whole orders by itself, I cleared a spot on my usual acclimation rack at the front of the tank, but I was curious how much different in PAR was the higher rack? So I grab my trusty Apogee 510 and decided to measure the 2 locations. The old rack at the front about 175 - 200 PAR. The new rack closer to the lights ... 110 PAR. So my assumption was completely wrong, the new rack is super low PAR, not higher than the previous rack.
So in thinking I was lowering the lighting on the remaining frag I had moved from the higher rack, I was in fact almost doubling it, lol.