Hi TASTY...
your plant should not grow vertically after the first 3 weeks of flowering.... It is all preference and some watering techniue... It sounds like you have maxed out yor pot..
do you have any signs of rootBOUND plants?
fdd grew some monster 6-9 foot tall plants in 8 gallon containers (i think).... he was growing outside....
In general, I dont like to see plants in containers smaller than 3 gallons... although there can be great sucess in 1 gallon containers when the plants are fed, flowered and given nutrients correctly..
picture ?
cheers