Hi - I am in a lockdown with limited kit and live in Africa so we can't order it online or have it locally in shops. This is a first time brew and I managed to beg, borrow and steal some old grain (Maris Otter), old yeast (S-04) and old hops (Fuggles). Using a 7.5L (1.9gal) pot for the mash and boil. Assuming I can work out a recipe for an ale with my ingredients (any suggestions would be awesome), how do I work out what water to start my mash with and how much to sparge water to use to bring it up to volume (excluding maybe some volume to add cold water and ice for cooling). I want to fermenter 1 gallon. Thanks.