We have a 500 liter watertank and outside of Europe we fill it only with water we first filter our selves.
To filter we use a filter set from Famous Water Germany. It are to parallel ceramic filters followed by two carbon filters.
The first ones filter 99.99% bacteria out and make water we take from almost all sorts of water sources drinkable. The turnside is that the filters get constipated pretty fast so therefore we have to clean quit regularly.
The carbon cartridges take out bad smell and tast, even chlorine from the just filtered water.
Since their is at least 2 bar water pressure needed to press the water through the filters we are looking for water taps with pressure. Otherwise we use our own water pump to get this pressure.
In Africa we travelled with our two boys with only 20 liters a day and so maybe we overcompensated now. But having plenty of water is a real luxury. Now we can take a shower after sporting, a hike or any other activity. We fill up every two weeks when we are with the two of us and every week when the kids are joining us.