After a long fast you should re-up on salts: KCl, NaCl, baking soda @ 1:1/2:1 tsp per 2L of water. The baking soda is good for your kidneys. I don’t actually know the sufficient amount for 7 days but getting electrolytes back in is important.
Coconut water is a good alternative source, too. For a 48h I do 500ml (which isn’t a lot because my body stores a lot of water and even after 48h I’m well hydrated). Then, I follow it with 500ml water + 2-3 tsp of baking soda about a half hour later. You can use this as a start for optimizing what your body needs.
Congrats on 7 days!