how many plants could 4...

4, 4ft flouecent bulbs grow completely?

It's impossible to answer you question without more information.

How strong light (Watts)?
What color-temperature (Kelvin)?
How much space do you have?
Etc...

If I remember correctly, 50 watts pr. square feet is needed.

nothings impossible. lol and i think they are 40 watt each, and we have a huge walk in closet with the plants posted up in the corner. we put tin foil all on the walls and shit

you could probably do two.

you think only two? i was hoping to put like 4 and maybe getting some more cheap lights

You need to know what type of lights you have they may be the wrong type for flowering. my guess would be no more than three plants and even then you would probably want to add some more lights in the flowering stage. you should check out the forum on lighting

Don't go buying a bunch of cheap lights just to get by . Find out what you want and save up for them. Do things right. Unless money is no problem.