How long does it last?

[cuy103]

I bought distilled water last week but didn't use it all.

How long can I keep the water?

Does it go "bad", ph wise?

 

[mr.greengenes]

Keep distilled water in a sealed container in a dark place. If it becomes exposed to sun light, eventually it will grow algae (undesirable). If you can, check its pH to make sure it doesn't go over 7. Water left exposed to the elements will take on a life of its own in a short amount of time.
Mr.Greengenes