PROCURU 1-Pack 3/4" FIP x 60" (5Ft) Stainless Steel Water Heater Flex Connector, Certified Safe (6WAA60-1P)

Thanks for that. I was wondering if 1/2" was too small for a 3" column but sounds like that works well. Now I just need to find some uncoated 1/2" somewhere. Was yours just the tubing or did it have connectors on the ends? The closest I've found is this: 3/4" CSST Water Line but I think I'd rather have the 1/2" and not sure if 3/4" is too large.