Here's my hard water wash routine:
Warm rinse w/ Calgon
Hot wash w/ Calgon + 1/2 scoop Tiny Bubbles, extra rinse.
Sometimes I think I can still smell a trace of detergent on the diapers when they are still wet, but then they don't smell like anything when they come out of the dryer. I had some minor repelling happen a couple of weeks ago so I added another hot cycle with washing soda only after my regular cycle. Problem was either solved or it was a fluke.