light question plz help +rep for any helpul info

hey well i just strated my flowering stage like two days ago but i was wondering hor away should the light be from the plant im using a 250 watt sunburst convertible ballast with a convertible ballast with the hps bulb right now i think its like 6 to 8 in away should i raise the light more????

as long as you have a good breeze your in the perfect range.