I have a 48" long tank with 3 AI primes and I'm getting a lot of shadowing so I'd like to add a strip light in the front and back of them. My Primes are about 13" above the water I think the new setup will remain close to that. I'm looking at the Orphek OR3s in 48" but was recommended to go with the 36" versions as I would waste the extra length as light spill (120 degree lens). The price difference isn't really a concern so I was just going to stick with the 48" but would that end up being too much light outside the tank? So do most people get lights the entire length or do you go shorter taking into account the spread?