Everything is prepared. Just need to get the family duties out of the way first (taking my daughter swimming) and then the rest of the day is mine to brew

First thing I need to check is roughly how much water will the grain hold? I will be batch sparging so as far as I know, the first batch of water needs to be half the total boil amount plus the extra amount that the grain will hold?
So, for a 6 gallon boil, how much water would I need for the first infusion? I will have 6.65kg of grain.
Thanks.
PS, There will be plenty of pictures (and maybe a little bit of video) to document this moment in history
