actualy, ive used salt that old.
it seems to work just fine, for when your in a pinch, though i would try to avoid it if possible...just to be on the safe side.
make sure its dry, and hasnt been contaminated.
-oozy-
I would be interested in this one, I moved and stared a new pail of IO at the same time, never had hair algae before and since then TROUBLE!!!! I addded RO to the system and STILL problems. Salt... Never thought about that, is expired though.
Finns
well i see someone was looking at this thread if this helps at all i was kinda in a pinch and used some of the salt that was a little over a year old i did 2 10 percent water changes on my 125 gallon tank so approx 35 gallons of water was made with the old salt and all of my levels stayed right where they were suppose so maybe it does go bad but the stuff i had didnt