Infinite, if the container is tightly closed.
I eat it too fast to find out.
Ban them for life.
Brine is typically a liquid mixture mostly of SALT. Salt is a preservative for many things.
no...salt, sugar, flour...none of these expire. your epsom salt package might have an expiration date..probably indicating shelf life....generally how long it can be expected to remain on a shelf before it's effected by moisture. moisture can case it to clump and get hard...but if it's unopened or well sealed it should not get hard and doesn't go bad or lose it's effectiveness.
simply buy the required amount of salt for the pool from a pool shop or other salt supplier and and toss it in the water.
Our pool supplier said at least 5 years, usually more.
Both table salt and sea salt will keep indefinitely as long as it's kept free of moisture and dirt. Salt is used as a preservative, so it has a very long shelf life too.
at the pool shop
Simply put any pool can be a salt water pool, even an above ground pool.
No. The salt is left behind in the pool , with the salt concentration becoming higher.
Add salt
Yes as a mater of fact that is what salt water pool normally is. With a salt water pool there is a electronic salt water chlorinator installed that uses the salt in the water to create chlorine. However if you don't have a salt water chlorinator and prefer the feeling of a salt water pool then there is no reason not to add salt to the pool as well as keeping up the chlorine yourself.