Bunkering drinking water
Those who always want clean and proper drinking water out of the pantry tap, have to observe important basic rules.
Take only clean drinking water from confidential water taps, use always your own tube and test the water before filling (e.g. sugar test: you agitate a tablespoon of sugar in a glass of water. If the water looks clear in the next morning, then it is fine. If the water is blear, you should better not drink it. Renew the water supply at every opportunity.
After bunkering add some disinfection agent. This might kill bacteria which remain anyhow. Disinfection agents are available in specialist shops as liquid, powder or in pill form.
In any case built a filter in the water pipe and change it in certain intervals, but at least if the taste gets bad or de pressure in the pipe releases. Filters are unnecessary at water taps which are only for washing purposes. It is handy to have separated washing and drinking pipes, then the filter has not to be changes so often.
Clean the tank at least once a year, the best time is in autumn.