I wouldn't leave them on all night the moon lights are mainly for saltwater but you could keep them on for an hour or 2 after you turn the main lights off or if you ever want to look at the tank at night without disturbing the fish too much
Bioibs are 28 gallons that's more than enough to keep saltwater fish as long as you get good flow you'll be fine I'd add a sump too there are people keeping fish in tanks 3x smaller there even are people keeping acropora in tanks under a gallon
Edit you could even add some light and put coral in...
hi everyone I'm john, this is my mixed nano reef it's a mr aqua 12" cube. I set the tank up November 25th 2012, feel free to ask any questions and if you guys want I'll post more pics in the morning.
here it is the day of the day of setting it up.
and this is it now
http://youtu.be/GmXjrM90_K4...
The tank is currently a reef I plan to upgrade it in the next few months once the coral starts getting too big once that happens I'm going to turn the cube into a planted freshwater tank sorry if I wasn't more clear plus the planted tank will be sumped so I'll have around 15ish gallons of h20
I currently have a 7.5 gallon 12" cube sumped mixed reef I plan on upgrading some time in the next month and want to put something in the tank and I was wondering what you guys segest it's already drilled so I'll have a 10g sump I was thinking a pair of apistogramma possibly or some dwarf tetras...
I just wanted to introduce myself I'm John I'm from Portland Oregon, and 17. I've been keeping fish for at least 10 years I've kept freshwater, saltwater, reefs, dart frogs, lizards est as of now I have a 7.5 gallon mixed reef and a 10 gallon PDF vivarium which I will make threads for shortly