Yeah, they understand that. They're just saying you might be able to get more life out of a 1000W bulb than a 400W bulb. It is plausible so I'd love to see an experiment using a decent sample group. Anyone up for putting up 100 400W fixtures with 1000W bulbs?You guys seem to be missing a pretty important detail here. If you are plugging a 1000 watt hps bulb into a 400 watt ballast, you are probably only getting the light of a 400 watt bulb right? I mean, if all it took to get the light intensity of a 1000 watt bulb is to get it to turn on at a lower input wattage than this would be the power saving breakthrough of the century. This is physics though, you can't just create energy from nothing. I think the actual light output of the bulb is greatly reduced when doing this, but who knows, stranger things have happened.
Sorry I don't even use HID, I was just going from memory of some of the prices I've seen online. Pretty sure 1000 watts cost about $100 don't they? Well anyway the point remains: why buy a 1000 watt for twice the price when you could buy 2 400 watts? I am willing to bet the 2 400 watts used one after the other together last longer than a single 1000 watt...damn $50 400w hps bulb where you getting ya bulbs from?