Most of the tests designed for water quality are on the expensive side (equipment and reagents).

If it's tap water and you keep it chlorinated to around 2 parts per million, it's fine--may taste flat until you reoxygenate it by pouring it from container to container.

Test strips and chlorine may be purchased from pool supply houses (and I have found them in larger grocery stores). Make sure the test strips will test at least down to 1 part per million.

Make sure the calcium hypochlorite content is at least 65%.

You may chlorinate up to 10 parts per million but don't drink it <img src="/images/graemlins/smile.gif" alt="" /> Chlorine will evaporate over time, and 2 parts per million is drinkable.

No chlorine in the water--don't drink it. I can't imagine that two year old tap water would be remotely safe to consume; most cities only purify the water and add about 1 part per million chlorine.

It's much easier to treat and store water in the largest containers available. In the military we commonly use 400 gallon water trailers and check the chlorine level two or three times a day....