Yellow leaf probleme

Hi, I'm a new grower and I have a problem with 3 of my plant. My setup is pretty basic, 500w halogen lamp 6 foot from the ground in a closet with little ventilation. See the picture any idea?

Id get better lighting first off, halogens are known for being horrible to grow with. If you have a low budget get 2-3 cfl's per plant. If you have a little extra spending cash get an high pressure sodium, 200w would be perfect for 3 plants. Make sure your using good soil, for new growers the more perlite the better. I use about 40% perlite in my soil, it makes over watering hard lol. Give them nutrients accordingly. Not sure if your using any because your info was vague. But i would do some research and honestly start over. You wont get much further then that though with a halogen light. If you could get an hps in there within a day or 2 you could turn that grow around but otherwise id invest in what you need, good soil, nutrients, lighting, ventilation equipment(fans), ph up and down, hygrometer/thermometer, and all that good stuff. If you don't have what you need you'll be fixing problems your whole grow.

Ok thanks for the reply. I have 19 plant with just one 500w halogen lamp. what light should I use for 19 plant? And I use miracle grow soil and nutriment here's the link of the product:


http://www.scotts.ca/smg/goprod/miracle-gro-liquid-quick-start-plant-food/prod10060012/
http://www.scotts.ca/smg/goprod/miracle-gro-premium-potting-soil/prod10190084/

for that many plants get a 1000w high pressure sodium imo. Also i wouldnt use miracle gro. Had bad experiences with it.