What's up guys? Need some advice for a friend. He's in the middle of installing a traditional OWB and is in the process of shopping for pex. I did a bunch of reading and couldn't get a definitive answer. He wants to know if he can use regular blue and red pex (like the water pipe kind) for his lines. I know you need oxygen barrier pex for a closed system, and you don't for an open system, but is this the kind of stuff you can use? Thanks in advance.