Hey everyone i need a little bit of help. i've got a nice little fellow growin, (its a ak47 x with northern lights 5 xdiesel) anyhow i'm looking to bring it inside and flower it inside, i got my buddies 1000watt sunlight supply inc. ballast wit a 1000watt hps bulb at the moment. however this is going to be way more power than i need, is it possible to use either a 250 or 400 watt HPS instead of thousand, are ballasts backwards compatible like that?