Thanks for the info
We're in an old house in Huntington Hills. The pipes I can see are not copper, but who knows what is behind the walls.
I am now looking at an RO/DI system. Though the fish tanks are small, we have many carvinorous plants in the house that also require RO/DI. I also use the RO/DI water in our three AeroGardens. I'm constantly at Walmart buying water (or so it seems). An RO/DI system would pay for itself in a year (based on my calculations) and be much more convenient.