Originally Posted by homebrewer_99
Actually, if mixed properly, at the recommended 12.5 ppm, it is safe to drink.
After 24 hours it's dead...ineffective anyway, and again, safe to drink.
Dumping outside? Definitely.
Safe to Drink? translation: you won't kill over dead!
Dead or ineffective after 24 hours? I don't think so.
Although the Mgf. may recommend that you dump it after 24 hours that doesn't mean it's ineffective. After all they are trying to sell more.
Factors contributing to the decline of effectiveness include exposure to sunlight and any load factor such as dirt, debris, insects that flew into an open container of it.
I've stored fresh unused solution for well over a month in a 5 gallon cooler and have never had and infection.
Here's a good article:
The good Dr. in the above article recommends dumping it after 24 hr. but like I said he's trying to sell more. If the undiluted solution lasts for years I don't see any reason why a diluted form in clean water and protected from light would not at least last for months. Mine certainly has.