Don't know what watt my HPS bulb is

alright i just got a high pressure sodium bulb and ballast from an old buddy in return for some of the eventual harvest, however i have no way of knowing how many watts it is... he said you could fit a ping pong table of plants under it so i was thinkinig maybe like 1000 watts or something but i really have no idea. Is there any way for to tell how many watts it is and how far away to keep the light?

take the screws out of the ballast and look for a sticker on the inside of the cover. Maybe check to see if its on the bottom of the ballast before you take it apart.
as far as the light distance question...hps about 3 to 6 inchs depending on the ventilation.