Equipment Profile and Top Off Water Question

Hi All,
In Beersmith, I've set up equipment for 10 gallon batches where I end up with an 8 gallon end boil.  The brewsheet tells me to add water to make 10g's which is what I want however, the recipe is just a double of what I'd normally do with my 5 gallon equipment setup.  In other words, if I just double the recipe I'll fall short of my desired gravity by adding the 2 additional gallons.  What am I not setting correctly with my 10g set up?  I'm positive I need to increase my grain bill to make this top off.  Anyone?
Thanks, Mike

My guess is that you didn't set the PBV to 10 gallons.

Minus boil off and trub loss = 8 gallons

If PBV is set correct, your grain bill should be ok to hit your PBG

If you have the five gallon recipe in Beersmith already just use the Scale Up button and see how that comes out