What is the "Shelf Life" for NSW and RO/DI water?

[sco999]

I have 2 20gallon brute containers. In one I keep NSW, and the other is for RO/DI water. My question is how long is the NSW good for and how long is RO/DI water good for? NSW container houses a maxijet 900 and a heater, which will run 24/7.

 

[andretti]

The exact shelf I don't know, but know, but as long as you are circulating it, it should last months. I do the same thing bacause I have two large tanks; a 300 & 120 (both reefs). So needless to say, I neeed a lot of water at my disposal. I make up to 300 at a time and keep it in a large container in my shed. Sometimes the same batch is there for 2-3 months. Just keep it out of sunlight and you'll be fine