That sounds like a good idea April and Andrea
I don't think above ground water tanks are too expensive to buy. Maybe a few hundred for a small one?
We have tank water at our house
Only because we do not get access to town water where we live! The water is always perfect for the fishies and it tastes better too lol.
Our water does go through a filter and stuff before it comes into the house but I think this is mainly to remove any bugs/dirt that has got into the water.
The only problem might be that the water in the tank could freeze in winter...?