No don't use galvanized steel. It rusts, and that's why people with galvanized steel water supply piping spend big bucks to replace it with either copper or PEX.

The only time galvanized steel will outlast grandma is when you use it for the piping of a hot water heating system. But, in that situation, all the oxygen dissolved in the water is either driven out of solution by the heat or reacts to form rust in the hottest spot, which is the boiler. All the hardness ions form scale in the hottest parts of the heating system, which is the boiler itself. So, the vast majority of the time, the water flowing in those galvanized steel pipes will be both oxygen depleted and ionically dead. The iron doesn't rust because there's no oxygen to form Fe3O4, and the pipes don't cake up with scale on the inside because all the scale forms in the boiler. So, in a hot water heating system is about the only time you wanna use steel water piping. I once had to replace one of my steel water pipes going to a radiator, and after about 40 years in service, the thing looked like a brand new steel pipe on the inside. No corrosion or scale at all.


PEX actually stands for PolyEthylene (Crosslinked). So, polyethylene is a very strong hydrocarbon chain, and crosslinked polyethylene has crosslinks between the hydrocarbon chains to increase the strength and rigidity of the plastic. There's no aluminum involved. The PEX tubing gets crimped onto special PEX fittings with a special crimping tool, so plumbing repairs can be done even when there's water leaking in the pipe, which is a great blessing.