How close to put my 400w HID?

OK so i just got a 400w hps kit like this one http://www.amazon.ca/LEDwholesalers-Electronic-Ballast-Hydroponic-Complete/dp/B003C2UOMM/ref=sr_1_1?s=lawn-garden&ie=UTF8&qid=1392665434&sr=1-1&keywords=400w+hps+ki and i was curious how far it should be from a plant in flowering to max out the light used with out burning it. Also if i start flowering at about a foot and a half tall and its indica strain how big should i expect it to be by the end of the grow?

About 2 feet on the light. You can play with it from there , move it a bit closer and then a bit farther and see what produces the best results. Indica usually doubles in size so around 3 foot tall. Some sativas will triple in size. But the rule of thumb for indica is double the veg height.

k thx for the info guys you just saved me alot of guess work with the light.

You can safely drop a 400w to about 6-8 inches if your grow area is properly ventilated and cooled.