Decided to give it a try. My wife has some anti-dust tape left over from her greenhouse. This stuff: Anti-Dust Tape at Menards. It still lets some light in down the center of the strip. I only taped off two of the white strips on each fixture. The other thought was to tape off individual led's for more even lighting, but it actually looks fine the way it is. The color is much better than with them all on. I lowered them another inch to 8" above the water, and I'm going to extend the light cycle one hour for the first week, then increase it until I see stress in the LPS.