added sparge water 20 minutes into the mash (153 deg.) resulting in a mash temp of 154.5
Based on boiling 7.75 gallonsliters at 1.049 for 60 minutes, this will decrease your wort by 1.75 gallonsliters, bringing your after boil OG to 1.060. You wanted an OG of 1.064. It looks like it will be under.