dude, get rid of the tin foil, thats first.. It may work for the Trailer Park Boys, but is not recommended.. Second, If this is your first grow, or second or third, just think of it as a learning expierence, and whatever you get be happy with it.. Even if you only get a quarter ounce, at least you gained more knowledge about cannabis cultivation..
1gram/watt.. Is the maximum you will get.. So a half pound is the most you will get.. And thats with everything going perfectly, and in perfect conditions.. So like it was said earlier, if yoou get 4 ounces, i would be ecstatic