a ballast runs your lighting system
You hook a bulb and a refelector hood up to in
Throw some plants under it
Wait 3-4 months
And smoke dope
it is gonna be hard to grow anything indoors without one
there are loads threads on this site that talk about ballasts spend some time reading them and find out what best suits your grow area
I started growing about 2 months ago
i spent a few quid on a good 400w ballist and hps bulb i had a few problems with the first crop but am about to flower a crop of 4 plants and i know that i have the power to support more plants for my next crop
The ballast and lights are a major cost but after that you have them for ever (a new bulb every once in a while) with no major cost to produce extra crops
My advise is just buy one and get it over with and plant some weed