It does sound a little different to any water service in a house that I have lived in. I guess if I was a potential tenant I would like to be told about the water system before I filled in my rental application. Would it turn me off wanting the rent the house? Not at all - but if I moved in without explanation I would probably be frustrated and confused. Sounds like they need a hands-on demonstation from you or your DH because your agent is probably confusing them even more.

Good luck.
That's what I was thinking - I would think it was weird, and might need a demonstration if I was confused, but I wouldn't harp on about it once I understood.

I think our landlord, annoying as he is himself, might have the same kinds of thoughts about the overbearing property manager we have. When they both come for inspections or whatever, he's usually the one saying its okay if we want to change things, whereas she cracks it if any room is untidy!