I've used bottled spring water before when I had to keep my reptiles for awhile at a place that only had well water. Didn't want to shock them by suddenly introducing all the bacteria and metals that well water has in it.
Sounds like you have a lot of animals that need treated water. You should really look into getting a bottle of the SeaChem purifier and just reusing those gallon jugs and treating a new batch of water every few days; if you go through it quickly there's really no problem with treating it and using it over 3-4 days. Over the long run it's a LOT cheaper than buying spring every time, and you don't have to worry about how honest a specific brand is being about the source and treatment of their spring water.