We have used DI water in ours for years at the other location and at my previous employer and nothing has ever happened that is corrosive. Our tap water is far from acceptable to use so we steer clear of that. We have the manual and did see that statement.
I only ask this because the supervisor before me attempted to do a study and cultured the water for a month and nothing ever grew, but since the research was not done correctly, it could not be used to extend the cleaning time.
Thanks for the advice!