JOHN... MY BROTHER!!!!
12 plants under 2- 1000 watt hps's
WOW
you are going to see the miracle of LIFE

Make sure you have tons of air flow.. pull the heat away from your plants

PULL......

Sativa has good advice
Put them in 5 gallon containers.. you can get them cheap at HD.. 3 dollars... or so
if this is your first grow, you may want to consider adding perlite to your soil.. many new growers over water and perlite will give your roots a place to go and get O2 ....if you do over water....

please post pics you're gonna have monsters...
and go bigger than 3 gallon!!!

: )