Straight copper pipe, at least 30cm long. 15 or 22mm diameter central heating pipe works well. (A hardware store may lend you a piece for a minute just to try this out) A circular neodymium magnet ...

PVC and CPVC have different sizing measurements. “PVC will follow iron pipe sizing (IPS) whereas CPVC will follow Copper Tube Sizing (CTS),” Smedley says. It really depends on the application.

I originally planned to go with traditional copper water pipes ... plumbers comes down to a few key advantages over other pipe types: durability, resistance to corrosion and easy installation.