I let my ro/di water drip into a big trash can(clean, never used for trash), next day it will be full, add salt, and power head, and mix it for 2 days. Change water and just add!
The way I see it, it's much easier to have your own ro/di unit in your home. It may cost a lot at first but if you stay with the hobby it will pay for it's self in no time.
I have been using distilled but my Kent Marine Hi S RO/DI showed up today. The bad news is I am in NJ for training for work so I don't get to play with it!