If you wanna run a 400w grow you should consider getting a small high output flourescent or CFL's to grow a mother plant with so you can clone & grow females each time under it, instead of growing from seed & having a 50/50 chance of needing to scrap plants. You should be able to do 400watt + the floros to keep a mother up without losing the slightest bit of sleep over paranoia about your power bill.