My tank is in indirect daylight until 4 or 5pm, then we turn on the normal lights. Often around 8 or 9 I'll switch to moonlight mode for the last hour or 2 before we go to bed, then they are completely off overnight. I started doing this in hopes of seeing more of my shy bristlenose plecos, but honestly haven't noticed any difference in fish behavior or activity. It's for our enjoyment and so the tank isn't the brightest thing in the house as we wind down our day.