I'd buy a rodi unit... But otherwise you should check every time you buy it. I have had anything from 0 to 200 in lfs water. I got my own unit so I know how it's maintained and don't have to suffer at the discretion of the lfs maintenance schedule.I get my RO form my LFS's I alternate between 3 sources. Should I check each with my nrw TDS meter to see which is the best supplier?
I'd recommend rinsing your bucket with tap and allowing to dry before you get a rodi refill.
Spectrapure has a refurbished 90g per day for 125
http://spectrapure.com/RO-RODI/RODI-SYSTEMS/Refurbished-90-GPD-RODI-System
Not only will your own unit give you control over maintenance, no more lugging buckets from the store. And if you need to do a water change when lfs is closed you can start producing rodi immediately instead of waiting for the store to open.