Hi,
The water to grain ratio is set in the mash profile. This helps us scale the mash profile to keep a steady water/grain ratio as you change your ingredients and grain amounts around.
Most of the mash profiles are built around a 10 lb grain weight and around a 1.25:1 water to grain ratio.
To change it, you can edit the mash profile (or edit a copy of one if you want to keep the old ones) and then go to the step you want modified and change the amount of water. The water to grain ratio will be recalculated as you do this.
Keep in mind even though most of the profiles are built around a 10 lb grain size, the actual amount of grain in the recipe is used to scale the mash profile to the proper size when the mash profile is applied to a recipe. In this process the water/grain ratio is kept constant.
I hope I explained this properly -- feel free to write back if you have problems.
Cheers!
Brad 8)