Can't adjust mash

Whenever I create a recipe in beersmith and add my mash step. I can't seem to override the "water to add" field of the "water/grain" ratio field.

I should also mention this is only when I choose BIAB method

Hi,
  For BIAB, BeerSmith assumes you are doing a full boil mash (i.e. everything you need for the boil is in the mash).

  If you are not doing that (for example adding water later or wish to mash with less than full volume) you can simply select a non-BIAB profile and work with that profile which will allow you to adjust water added and water/grain ratios.

Brad