220 runs at a lower running amp than 120..It would be a little cheaper to go with 220.. But if ya have to add a breaker and wire then,if your on a budget. Wire ain't cheap. I use 120 with a 1000 watt digital ballast and my running amps are 4.7..only about 30 extra bucks a month.. Gotta add all the timers and fans,pumps and things,too. Using 220 would use 2.9 or so amps,running.. Starting amps will be the same amount of current.Like when a fan start up and then the running amps drop.If it's a 220 fan. Did any of this make sense?