I have a question about going on vacation. I'm visiting Athens, Ga this Wednesday-Sunday and have no one who is trustworthy enough to watch my tank. I am still in the cycling process and only have 6 snails (which have survived through it all

They're happy just eating the algae off the rocks, glass and crushed coral and I've never supplemented their diet with algae or anything at all. What I'm worried about is turning on and off the lights, I don't have a timer. I have just the basic flourescents that came with my basic hood. Should I leave them on for the entire time away, or off or invest in a timer?
Will hopefully be able to buy a fish or two when I get back, but I wanted to wait since I knew I'd have no one to help.
Any suggestions?