Has anyone had any experience with an older open loop that has not ever been back-flushed and cleaned? I have a customer with about a (5) year old system that has never been attended too. The water in that area is very high in calcium and areas where the system had small leaks had major deposits left behind. Is there any worry with chemically cleaning a system this old if it developing leaks in the coax? I planned on using something less harsh then ice machine cleaner to clean this system up with. Any thoughts?