Should I leave my snails lights off or on? [I Have a Fish Tank]

I have a 5.5 gallon planted tank with one nerite snail and live plants. I am going away for 3 days on vacation and no one will be home. Should I leave the tank lights on or off? I'm afraid if I leave them off for 3 days the algae will not grow and he won't have much to eat. But what do you think is worse too much light or darkness for 3 days?