I'm going to replace some PEX plumbing joints in my crawlspace that apparently have suffered from zincification. I did not install this plumbing so I don't know what brand the fittings are, however I have installed PEX before and I have all the tools. My questions are: is there a way to find the zinc content of brass fittings commonly available to me? So far, I haven't been able to look up this info. If I can verify that the zinc content is low enough, I feel better using brass than poly, but if I can't, I might rather use poly. I've avoided it in the past for no other reason than it seems cheaper to me, but if it works, it works. The problem though is the lower diameter inside the fitting. Does this actually cause a noticeable issue in practice, in terms of lower flow? That really wouldn't be acceptable. Thanks.