Bathroom decoration when the dark pipe with copper or PP hose that kind of good?

Bathroom decoration when the dark pipe with copper or PP hose that kind of good?

I give you a suggestion, the toilet water pipe can be considered with copper pipe, copper water pipe must not, because copper cannot be used to tap water pipe, will be poisoned, or use PPR or PE pipe, environmental protection and safety

Copper tube, of course. It's expensive. Now PPR pipe is used