If your just cycling the tank, no live stock or inverts in the tank then IMO
just leave everything off including the lights.
Check it in the morning. No reason to possible foul up equipment with debris getting into things while your tank clears up.
Once your tank clears turn your pumps/power heads on. You may have to blast the rocks with a turkey baster to get sand off of them.
Good luck and can't wait for pics!