Mash water ratio with decoction mash

I am using BeerSmith Brewing software.
I think it gave me an incorrect value for mash water.

I brewed a 11 gal batch of budvar, 20lb grain bill.
I did do a tripple decoction mash

The software said to mash in with 40 qts of water.
I usually do 1.25 qt per pound, this would be 25 qts.

Anyway, I had a very thin mash.

Peter,
 Traditional decoction mashes are often done at much higher water to grain ratios than standard infusion mashes.  Up to 2-3 quarts per pound are used in some cases.  This should not adversely affect your beer in any way, particularly if you did the full triple decoction which usually yields better starch conversion than an infusion mash.

 I have several references, but one good discussion is "The Brewmasters Bible" by Stephen Snyder p 31-33.  He recommends 2-3 quarts/lb for decoction mashing.  Most of the BeerSmith decoction profiles use 2 qts/lb as a standard.

 If you would prefer you can still decoct at a lower water to grain ratio - for example the "Decoction Mash, Triple Lager" is done at around 1.5 qts/lb based on Noonan's book "New Brewing Lager".

 As always, you can make your own mash profile if you prefer, or copy one of the existing profiles and adjust the water amounts down a bit.

Cheers!
Brad