How long would it take water to stagnate?

[Psye]

Hi everyone,

I keep a bucket of topoff water near my tank. The bucket doesn't and doens't have a lid on it. I was wondering how long it should sit w/o airating/circulation before it would be dangerous to add it to my tank.

Thanks
-Psye

 

[this is me]

Put a lid on it. Even with a powerhead, put a lid on it.
You don't know what might fall into it.

 

[Leroy]

Clean RODI water in a clean bucket should last a long time with no bacteria to grow causing any issues. Give it a good sniff test, let the nose be your judge.