Fresh water filters....
John,As far as I've been able to tell, marine water filters haven’t really kept pace with the Backpacking world (My other hobby). I recommend you check into products from sources like REI. Example: Katadyn Combi Plus Filter - has a pump, sits beside your sink, removes chemicals, bacteria, and viruses. You can run the nastiest stump water you can find through this filter and get pure "tasteless” drinking water. Filter is good for 13000 gals before replacement. There are at least ½ dozen manufactures to choose from. Check it out.Greg