How long can RO/DI water last ?

[lubeck]

I got a RO/DI unit for Christmas so i have been making water some for my fresh water tank. and i mix the rest for water changes for the salt water tank. so how long can the salt water last or the fresh water? i would say i use the water before a month goes by.

 

[bonebrake]

Be careful using RO/DI for freshwater tanks. RO/DI has an incredibly small buffering capacity and the pH can sway wildly unless you add some sort of buffer to it before you do your freshwater water changes. As far as shelf life, I have heard mixed saltwater can sit for a few months with no ill effects. Stir it or mix it for awhile before you add it though if it has been sitting awhile. If you store it somewhere and shake it every other month or so it would last a very long time in a sealed container in a room temperature, dark place.
:joy:

 

[jumpfrog]

I run a pump in my fresh water container. I'm sure that as long as it used in a month it will be fine. If you're using it for top and water changes you're probably turning it over much more than that.
I use ro/di for my discus tank but I do use a buffering agent to bring ph and alk up to the right levels. Works great and the fish are very healthy.