So you are no longer on the mains, it is your responsibility to ensure that the water you drink is:-
1) Safe 2) Plentiful 3) Available when ever you need it.
Within the first few weeks on moving we discovered the issue with option 1. My daughter developed a stomach bug, not the ordinary kind that is gone within 24 hours, the sort that hits you unexpectedly and lasts for several weeks, but seemed like months. Along with it came vomitting, so the joys of tackling both ends of a sick child became an art form, to ensure the minimum of clean up. She became very good at target practice. We went looking for ways to clean up the water, we were drinking from our galvanised tank. Initially we made sure everything was boiled, but that is rather tedious, so we went looking for a filtration system. To get one professionally installed with 3 types of filter, 1 meter of ultraviolet light, an alarm and controls was approximately $5,000. Until we hunted across the web for an all in one unit that you can easily fit yourself from around $1500 http://www.cynortic.com.au. Fitting the unit was straight forward, screw to the wall, connect the water and plug in the electricity. Changing the filters every 3 to 6 months was pretty easy.
The first issue we encountered was the 1 meter ultraviolet bulb which kills off bacteria and other nasties. The bulb sits inside a long glass tube to separate it from the water, it looks like a very long test tube. So not only did we have to replace the bulb but the cracked glass tube. We then needed parts, unfortunately the local distributor we had purchased the unit from was no longer in business, so we had to get parts from Western Australia. It meant rigging up the unit to work without the bulb, whilst we waited for parts. The bulb was poorly packed and was broken, so we had to get another one sent, I asked for 2 so we had a spare. They happily replaced the broken bulb free of charge. Then we had issue with the electronic controller unit, and when we went to contact the people in Western Australia they were no longer supplying and we had to go direct to New Zealand. New Zealand replaced the unit under warranty, with a newer model which had extra functions, so it took a few emails back and forth to establish not to connect this wire to anything else. The unit uses standard paper and carbon filters which can be purchased in most plumbing and irrigation places, it is worth shopping around as the price can vary considerably. My daughters bad tummy did eventually disappear, my kids understand how essential it is to safe drinking water even for first world countries.