Originally Posted by PerfectDark
They are mainly for appeal at night some have white lenses some have blue. If your lights were completly off there would be no ill effects on your tank. You can specifically set up a system to mimic the lunar cycle. But that takes a lot more than just clicking on lunar lights at night. And in that circumstance there is a benifit, as corals use the lunar cycle to spawn at a specific time.
thats good to know,
I've not seen them in person (just pics here)
they look pretty cool.
I'd definately consider them if (when) I upgrade my lighting