4ft led fixture

[sphelps]

I'd think long and hard about this as I'm guessing you're epoxying these boards down making changing them later rather difficult. Shelly did probably as good as it gets but it's still going to be awfully color spotty. I can't imagine why anyone would recommend this quantity and ratio of LEDs, you'll end up running whites at like 30%, blue at 100%, and reds and greens at 5%. Especially with 45 degree optics on the white for a 20" tall tank, is the plan to hang the fixture really high?

For a little more you could have gone with 3 drivers powering with 8 boards of blue, 8 R-blue and 8 Neutral white and I wouldn't use optics at all. I don't think reds and greens would be much benefit if you use neutral whites but if you really wanted them after trying this combination you could easily add them with a lower powered string to prevent spots.