Sorry it's the meds. LOL

No the extra power is never there. The current that passes through the ballast is pulled not pushed. So power useage is from the bulb side and you save by not ever using a full strength bulb.

But if the component in a ballast are smaller and say you pull 1000 through a 600 things get real hot and blam. I don't want to be around.

I think the company would just make 600's and sell them for 400's and 600's so you don't have two productions for similar items. Would be a good deal on the 400.

tinytoon I would like to here what the manufacture says also as it's new to me.