ckelly78z said:
Would it help keep harmful pathogens away by putting in a drop or two of chlorine when finished with the filling process on each tube ?
There are several "poisons" that can be used to treat water, so pathogens do not grow as easy or as fast or at all. Chlorine is one of them. Food preservatives (as used when making home made jams etc.) is another typically easily available option.
For the situation where you need to use water, that has been stored in a location where it gets warm/hot for a prolonged time, boiling the water for 20 minutes is a viable option.
I take this reference/option/recommendation from aid-worker friends who lived in Africa for 18 months.
As I recall, the country was called Niger (the location was just south of the Sahara anyway). In the city (the neighborhood) they lived in, they did have piped water, but the supply was very erratic, and would frequently be off for hours or days at a time - so each house had its own water-tower, and the water would very naturally be heated to the quite high outside temperatures, that a location just south of the Sahara has on a regular basis.
So after some simple filtering of the water (the filter was discarded daily, so it had to be simple and cheap), they ALWAYS still boiled it, at full boiling, for at least 20 minutes, before drinking any water from their own water-tower. This process kept them in good health for the duration of their stay.
On an other note, if the water-tower-tank does not get very warm, on a regular basis, then piped city water (or water of similar original quality) might be just fine to drink as is, even if used directly from a storage tank.
One example that comes to mind, is from the mid 1980'ies, where I lived in Nothern Ireland for many months, and the different flats I lived in during that time, all, also had a water-buffer/storage tank in the attic. And I did not think twice about drinking the water from the tap in the kitchen or the bathroom. Perhaps I should have, but being young and un-informed about the local customs, I just behaved like I would at home (Denmark, Europe) where tap water is considered to be very safe and of very high quality.
Now, I have felt a need to add these examples, to my comment about risks (Legionella in particular) as I mentioned in a comment above, as I do not want to only talk about risks, but would much rather like to focus on having enough information about safety and risks, to be able to find easy to use, and easy to do, solutions .
All I am basically saying is, that storing water, so it is still safe to use and drink, does need some consideration and care. But when that is done, water can be stored in many different ways, for surprisingly long periods of time, and still be very safe to use and drink.