Ok the reason it is streched you don't have enough light intensity or it isn't close. Make sure you put your 250 watt light as close as possible. You also need to get a oscillating fan on the plant it will help the stem get more sturdy(Make sure you oscillate it don't leave it on directly close to plant will stress it). If it has white hairs, it is female. You really need to use either alot or CFLs, or High pressure sodium or Metal Halide, HPS is better for flowering. You will get better yield if you throw in like 7 cfl. Use the double y adapters you get at lowes or home depot. Put atleast 7 like 6 in off the plant from all angles. When you induce flowering, By using a timer( 12 hours light on, 12 hours of light off) In a totally dark room if there is light leaks it will hermi on you. You will flower this plant for atleast 2 months up to 3 depending on if it is hybrid or sativa or indica. It will double or triple in height in flowering, you need atleast a 5 gallon pot, don't use any time release ferts, use either fox farm ocean forest potting soil or miracle grow organic soil( this has bad fungus gnats easy to take care of with neem oil) You will need supplemental nuts in flowering stage, low in N high in P and K. These are important will make sure you bud gets big. You can expect from low lighting etc( maybe tops 2 oz this is an over estimate depending on how you take the info I give you) Likely you will get a .25 of ounce to .75 ounce. I have used CFL's they work great so if you don't use the other it will work just get like 7 or 8 of them and put them close..... The aluminum foil needs to go, use mylar, the cheap version is the emergency blankets at walmart and kmart. These will not create hot spots like al foil. Good luck....... Smell will become a issue in flowering.

The best thing you can do for yourself is goto barnes and nobles and pay 25 dollars for Jorge Cervantes Medical Marijuana Horticulture. It has all the info you need to become more educated at what you are doing.