I have Zurn PEX with the old brass fittings, put in about 15 years ago. So far, no problems with it. But I have had some problems with galvanized fittings that are attached to it. For instance, galvanized threaded nipples threaded into the brass PEX fittings under sinks for the water supply. They have been corroding and I've had some leaks. My water is good, not hard or extreme in pH. I am trying to figure out these galvanized failures. The parts were originally bought at big box stores, do they carry a substandard quality of galvanized? or is it to do with the connection to the brass PEX fittings? I have several of these threaded nipples that I need to replace, what should I use and where should I get it? This has me on pins and needles because these leaks can cause a lot of damage before you even notice them.