(2) 400 watt hps VS. (1) 1000 watt

I,m planning on running 220. How would my electric bill compare? Thanks

Um 20% less with the 400's? but wait, your running two ballasts. Probably about the same would be my guess. I know there is a 600w ballast that you can run two lights off of. Maybe you could do it with one, then you would save with the 400's

your bill wont go down at all....a thousand watt light still pulls a thousand watts...like say your 1000 watt ballast pulls 10 amps at 110 volts at 220 it pulls 5 amps...but it pulls it through 2 wires...2-5 amp wires so your bill wont go down

Actually running things at higher voltage is slightly more efficient... Sometimes more than slightly.. And yea the rated wattage is for the bulb itself.. Ballast consumption is above that, and rarely mentioned..