Cheap but effective set up

This is a 70 HPS in a closet. These plants are about 45 days old. for the first 15 days or so I did not have the HPS, they sat by the window. So I know they are small for their age. The two on the left are drastically behind the other two, considering trashing. I have been using fox farm grow big at 1/2 strength every other day for the last week. What you see as my reflector is a sun protector for a car windshield. Growth is very slow. I am looking at some 47w CFL to put around at least the two good looking plants. Good idea or bad idea? Can/should I buy a higher wattage HPS bulb for my ballast? If you can see in the pic it is a simple outdoor fixture that came with the 70w bulb. I will probably only flower these two plants so will I be good with the 70W when I start to flower?

Alright I am dedicated to making the very best out of this, so please give me all the info you can. Please give me some suggestions to maximize my final out come. It would be much appreciated.

stop!!!! you have started at least 4 threads on htis people have already given you advice. This is just getting obnoxious!

plants need blue spectrum light to grow, your 70w hps is only good for flowering really, unless you have something with more power like a 250-600w hps.
They are the smallest 45 day old plants i've ever seen and really aren't worth flowering, you may get a little bud or 2 though if they are female.
If it's sunny ouitside, put them outside, that light is obviously no good.
Add some CFL's pretty close to your plants.

WOW 45 days thats way under lummed those plants should be at least 12 inches high and ready to be turned to 12/12 ... Dont waste your time with such small lights ,Get some 400w Hps or 600w Hps if you really want to grow properly ...No disrespect intended bud but there really under growing big time ...

Cheers and better luck with your growing in the future