I only go one at a time because for one, it's expensive to have them running doing nothing. 2. puts strain on your games and makes you have more burnt out bulbs. (you know it's going to be the GI bulb that's under 3 ramps to get to and ground braided in). 3. cuts down on heat in the house. Ambiance is nice, but I can get that when I have a house full of people and have to have them all on.