T5 light with a tent set up?

How many plants can I grow under this set up by keeping my light on 12 12 from seed to finish?

Here is what I'm using

(T5 4 foot) http://www.htgsupply.com/growlights.asp?categoryID=1&subcategoryID=107&typeID=71

And the tent for it Grow Tent - Mother Keeper 48 x 20 x 48

i have the same light.. its excellent for veg but not sure on bloom.. straight 12/12 from the start i would say you could fit 4 plants under it the whole way through..

anyone else