i run a 400 MH 18/6 and it costs me around 6-7pound a week max!im about to start my second grow i got a white widow fem and a skunk 1 fem last time i used flourecents on some easy ryder but im gonna switch up the light i was wondering if anyone new how much a 400 w mh whould change my eletric bill i dont want it to get to out of hand