Beersmith Mash In Low?

Hello all, I'm trying to figure my third all grain batch using Beersmith. It seems as though all three times I've entered my ingredients, the mash in volume of water seems really low. I'm using a chest cooler with manifold, single infusion. If beersmith is recommending a pre-boil volume of 6.7 gallons, why is it consistantly telling me to mash in with 13 quarts of water. After grain absorption and leftover wort that doesn't make it into the pot, I end up with around three gallons. I have my efficiency set at 70%.

I thought that I was shooting for a 1:1 volume of initial runnings to sparge. Can I fix this discrepency in Beersmith or do I have to just wing it?

you mash with 13 quarts, then sparge with another 14 quarts. that'll get you the right volume. sparging is basically mashing at 168 for an additional 30 minutes (batch sparging)