Electric bill...?

Hey I'm only going to be growing one plant in a grow box with a cfl and i was wondering if there is going to be a big change in the electric bill? or in better terms how much might it go up?

Umm with a cfl your bill wont move unless it an actual 200or 300 watt bulb not equal to but actual wattage the big 18-20 inch one.You can actually lower your electric bill by changing your house bulbs to 26 watt cfls and then buy a 400 watt hps and grow a real plant for less money..

So if I were to put this bulb -400W HPS Mogul Base Bulb / Lamps ED18 into my box it would be able to grow a plant from start to finish?

I would say depending on how big your box is and how well ventilated it will be, however you'll need a ballast and some kind of reflector for that bulb.

http://www.prolighting.com/soush400q-k.html

Check out some complete setups for reasonable prices.

High Tech Garden Supply

I want to get the 400w that's only $119.95 probably over a buck 50 with shipping, but still would be worth it.

If you must only grow one plant go with the 175w, although growing only one plant is a waste of time and money, I would reconsider your growing area and grow more than one plant.