I am not sure what the answer is about storage time, but I just make two weeks worth.When I started out my build I in tended on using my apex to work just like the Genesis Renew auto-waterchanger, I ran into some issues with my saltwater storage, I cant seem to find any real good information about how long saltwater can be stored, temp, and mixing. I'm curious how what your approach was in tackling this problem. Nice looking system, I'm hoping for the same results, my tank is a year old and I have enjoyed every minute of it. I have to admit the most fun was building the system.