Ok, so you're saying we should keep a big jug of water with D.E. in the bottom and drink from it during the day.
Correct.
Do we just keep refilling the jug with more water and not add any more D.E.?
Correct. Each time you add a little more water you will dissolve a little more silica on the bottom.
How much water per D.E. or does it matter? What would be the minimum D.E. used per how much water?
It really does not matter as excess silica will just settle to the bottom and get dissolved little by little. I add a spoon full of silica to my gallon jug. This should last at least 2 years, but I normally dump it out and add fresh silica ever 6 months.