I took a different approach aboard Salty... We have 300+gal. water tankage and normally fill from a well used water system at our home marina, so I don't filter when filling. I shock the stainless steel tanks once a year, flush, then add a little bleach with every top-up.
For drinking water, I added a dedicated tap in the galley which is fed through a 3M drinking water filter.
This filter is about as good as you can do without having an RO system.
Regarding storing your bulk filling filter, I do like Steve suggested for the 3M filter we use on our RV drinking water. Drain, refrigerate, then toss yearly.