Question about lighting

im currently vegging 6 plants under a 105w ecoplus, its been about 3 wks and im going to 12/12 soon,
will i have to wire a hps light to a ballast or is it plug to the ballast then plus to the wall?

more info needed.
(1) how tall are the plants?
(2) vegging should take 4/6 weeks(fact).
(3) and explain your electrical situation a bit better.do you have a lamp and ballast???.
(4) is the ballast correct for the lamp spec??.