you should use those support sticks when the plants have so much bud they are about to fall over. Like the others said you should make the stem stiffer by putting a fan directly pointed at them to increase rigidity. Your light might not be powerful enough if you are that close and they are still stretching. I would lower the light as much as you possibly can without having heat issues to the tops of the leaves. Good rule of thumb is that if the top of your hand feels warm or hot at the level the leaves are at then they are too close.