A couple responses.
--If you can dry it out completely, you can store and reuse any filter cartridge. Stored wet they tend to develop mildew and bacterial films, which can sometimes be reversed with a bleach solution, but it's better to dry them.
--Alcohol fuel has less energy than white gas or cartridge fuel, and it will take LOTS to boil many gallons of water. You can ballpark the amount needed by running some tests using your stove and a measured amount of water in the intended pot, then extrapolate to your cooking and drinking needs.

Cheers,
_________________________
--Rick