Good information to know. I have a 65g that's low tech right now and needs to be upgraded to a CO2 system. My plants are on life support with Excel at the moment.
There is another location for Minneapolis Oxygen Supply in Bloomington, do they have the same service (i.e. a shiny for a shiny)?
I have no idea. When I called on the phone they were apprehensive to say they had them on hand for exchange, but when I showed up in person they acted like it was normal.