Phantom 1000w Dimmable Ballast...

I got a few of these when my local store was running a sale. With the size of my next grow, I will not be able to use more than 600w lights. Can I use a 600w HPS and turn the ballast all the way down? Is this inefficient in any way? Am I better off selling these and buying the 600w ballast?

sell those bitches and buy some solis tek matrix!

I think I remember reading something about the phantom (or probably most any digital ballast) starts up at full power, meaning 1kw, if you're talking about running a 600 watt lamp on that ballast I don't think so. The only way you'll be able to run those is with a 1kw lamp dimmed.

If I do use the 1000w bulb and dim it down as low as possible, will my energy consumption still be the equivalent of a 1000w?

Unless the ballast specifically states it can run bulbs other than a 1000 (I have the galaxy sun select 1000w dimmable, it'll also run 400 & 600 bulbs) then running a lower bulb on a dimmed setting is a really bad idea.

They are designed to dim the highest wattage bulb they're rated for. I think it has Something to with amperage, I can't remember but I do know they bare not designed to work (unless it specifies it can use smaller bulbs as well)

I have the Phantom 1000 and it is dimmable... I don't recommend running your 600w bulb on it because, like dbkick pointed out... they run full charge for the first 15 minutes at powering up. Plus, they shut down if the light gets too hot and will not power back on until cooled down. Also, the dimmable part is simply selecting a percentage of power that you want to go to the bulb. Who's to say that 75% or 50% of a 1000w would be equivalent to the full charge your 600w would require. IDK... It just seems way to complicated to have to think out for a newer ballast. Can't you just switch to 1000w lights and then use the dimming feature so it isn't overkill for the size of your room?

Good Luck!