All Grain Yeast Starter recipe problem

I'm trying to make a 0.5 gallon AG Yeast starter with an OG of 1.040 using BeerSmith.

When I make my recipe BeerSmith states that I need 2.5 gallons of water, which I think is way too high.

How can I fix this to make sure that I have the right amount of water?

I would guess it is assuming you are going to boil for 60 minutes and also lose some wort in the kettle, etc.  If you are using DME or LME you only need to boil for 15 minutes.  Also, you can uncheck the "Set Boil volume based on equipment" and enter the volume of water.  Just estimate how much water will boil off in 15 minutes instead of an hour and add to .5 gallon.

Thanks!  I'm surprised that I missed the check box for volume.

Cheers!