Good for you! Enjoy that Rodi unit.
After you change the filters in it the first time you won't want to drink what's coming out of your tap anymore...
There is no need to store water for a FW water change. Stress Coat and other similar products work instantly to neutralize the chloramines/chlorine.
I do my water changes using a Python and simply pour the correct amount of Stress Coat into the tank while it is refilling...and poof, no hassle water change.
I have some very large FW fish, including Oscars, and their water might be considered 'dirty' by some immediately following the first meal after a water change...