One as it enters the boat and a second one dedicated for drinking. Add to that a bit of bleach to the main tank and you're protected along with that sub-micron filter lasting a lot longer.

If you have the time I add a third filter. A two stage (daisy chain) filter under sink. One of about 2 to 5 microns and then the final ceramic sub-micron (.2) for the bugs.

If I added the second stage my filter would last a lot longer. In the past, the ceramic sub-micron ones were only $13.00 and while cruising full time we had to replace it every couple of months. The price of the replacement is almost 4 times that of the old one. I think it's time to add that second stage.

I've never had a problem with a ceramic filter's flow as a dedicated drinking filter. I would guess that if I tried to shower with it I'd be unhappy with the volume. Hmmm? I guess it would be a kind of automatic water saver.