Storing saltwater?

[tastingSalty]

If I mix up a batch of saltwater for water changes, can I use part of it and then store it in an airtight bucket to use like a week later if I airrate it again?

[kfisc]

You could keep it for awhile if you have a pump going and keep it at correct temp; maybe a few weeks, depending on how much is left (say five-10 gallons or so). I wouldn't seal it up.