Can i run a 600w globe in a 1000w digi ballast on 600w?

So ive just bought a Lumatek 1000w dimmable digital ballast, im growing from seed in a 1.2m x 1.2m tent while im house sitting, and would only need a 600w MH globe for veg, but i would want a 1000w hps for flower. the ballast can be run on different settings, 600w, 750w, 1000w, super lumens (1100w)
So can i just buy a 600w MH globe to run on the 600w setting for veg? or will i have to dim a 1000w globe?
On this website it suggests i can run a 600w globe on the different setting
http://www.lumatek.co.uk/index.php/products/electronic-ballasts.html
Help me out people

[h=4]Lamp Replacement[/h] Be sure to disconnect the power source before changing lamps. Always use the specified wattage of lamp. The Super Lumen range of E-Ballasts are specific to one particular wattage i.e. only a 400W lamp should be used in a 400W ballast. However, the Dimmable Multi-Watt range of Lumatek E-Ballasts can drive lamps corresponding to the particular E-Ballast output settings i.e. the 400W Dimmable E-Ballast will drive both 400W and 250W lamps.. Lumatek recommends lamp replacement every 6-12 months.

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From: here

But don't take my word for it or the website - send an email to their support to confirm if you have reservations.

If it's the dial a watt version like I'm thinking then you should be fine setting it at 600 and putting a 600 bulb in

as it turns out i can buy 1000w MH bulbs cheaper than the 600W bulbs, so it doesnt really matter, i will just get the 1000 watter and dim it down
Thanks for the input guys