new to saltwater.

[thebigo]

Hi all.
I've had tropical fish for a while and have just got a 37 litre / 12 Gallon (?) saltwater tank. There isn't anything in it yet apart from water and sand as I want to make sure I don't kill anything too early...
Anyway, can anyone tell me if I need to run the Venturi skimmer constantly or can I turn it on for a few hours each day? It's pretty noisy as it gurgles away.
The tank has a refugium with a plant in it, sponge, ceramic rings, heater, etc...
Having browsed through the site so far, seems like it's very useful. Maybe one day I can help provide advice too - although it may take a while.
Cheers!
O