Quote Originally Posted by piu58 View Post
I have used the stock solution over a period of 2...3 months without any degradation. For 1+1 dilution I filled small bottles which remained unopened until I use them. They last even longer, more than half a year.
Thanks Uwe. That's actually pretty good I think. I have 2l packets for the most part, so glad to know I have a reasonable chance of using it up!