Bleach is standard for bacteria The filter is only to kill what may be left and to get rid of the chlorine taste.

To filter water before it enters the tank is problematic, especially when catching rain water. We catch rain water all the time using the entire boat. We just wait for the first bit of rain, scrub the deck, wait a bit, shove a screen into the filler hole (to catch hair and big stuff) and let it fill. We can get 300 gallons in about an hours worth of good hard rain. It's the best water there is. The tanks stay pretty clean. Since we're cruising full time we use them and go to sea (the action of the boat in 6 foot confused seas scrub the tanks). If the boat never left the slip it would be different.

Our general hygiene concept is that if we're too cautious with what we put into our bodies we will get sick. A friend of ours has a regiment of healthy foods and filtered water. He joined us in Bocas Del Toro and Kuna Yala Panama for a couple of weeks and got so sick we thought he was going to die. His sickness lasted most of the time he was with us. Not from what we had on the boat but from going out to dinner. As humans we need to ingest some germs to keep us healthy. Too much isolation and our bodies aren't prepared for what's out there.

In the 10 years we've been cruising outside the U.S. we've never been sick. Not because we filter the water but we believe because we're not anal about being completely isolated from organisms. Just a bit is healthy.