moon lights

[Rikko]

What I love about that is they don't ever want to try and guess what the wavelength (range) of 'the moon' is at depth.

Don't worry about watts of moonlighting - that's totally irrelevant. Look instead for what sort of coverage you want. I find a 4 foot tank starts to look too glowy after 3 LEDs - even a single LED looks good, and you don't have to worry about geometry. Having the lights places at mathematically precise intervals isn't always "right" - when I built the moonlights on my planted tank I used 7 LEDs and 5 of them were on the left side of the tank.. It gave a nice light gradient and several of the fish stayed under it whereas other avoided it completely.