What is the correct duration of a salt test?

[Eville]

I wouldn't go much past 20 days. Water starts to evaporate, ya know.

isn't that kinda the point?

[NullSmurf]

isn't that kinda the point?

The obvious sometime escapes some.

[Eville]

The obvious sometime escapes some.

For the record, I did realize you were being sarcastic, as was I.

[pmp]

Usually takes 24-48 hours to finish. Its correct when its stops changing. So in your case your hygrometer is pretty accurate. If its adjustable just dial it up 1%.