Appreciate HELP with my setup please!

I have a 4x4 area in a shed outside. I am going to get a 600w hps light. Does mh really make a difference for vegetative if I'm trying to keep costs down or will the one do fine with both stages? Also, there are 3 windows. Should I completely seal them? I'm trying to figure out the best thing to do for ventilation and co2 issues without purchasing a lot of extra equipment IF I don't have to. Won't be a problem to cut some vents if necessary. Also, would a 1000w be even better for this area or waste? Thank you for any input...

Mh is a big difference in colour, conversion bulbs can be found pretty easilly, or you can suppliment the hps with some flourescents.

Keeping windows sealed is an issue of stealth, entirely up to you there.

600w should be suffiecient, but more is always better.

What I'm wondering with the windows though is obviously need to block light but what about letting a little air in?

let the air in from a vent on the roof where no light can escape, one vent for in, one vent for out. and you really only need one actual ventfan, I would suggest at least 250+CFM. I would put that ventfan to pull air from the room through the light and out to the top of the room. the other vent in the roof would have a 4" dryer hose attached to go to the bottom of the plants. (since heat rises.)

or I could just be really stoned.:stoned: just hooked up a 32"HDflatscreen to my PC. and likewoah.

Does it get cold where you are?
Is the shed insulated?
if yes and no, then youre going to have problems with cold when your light is out during flowering.

About the venting, I would seal the windows and vent through a hole in the wall....much more controlled that way.
And yes, a 1000 Watt would be better, but the issue is heat....you will need some very good ventilation with a 1000 W in 16 Sq. Ft.
600 will be fine.
And I would get a HPS. If you have the money, get a switchable ballast. Or, like hombre above me said, get the HPS and use blue spec CFL's around it.

Good luck and keep us posted!