My water heater died this weekend. Apparently West Des Moines has super hard water - not completely cured by my water softener. The plumber was trying to sell me a clearwave magnet device to help. It sounds like absolute witchcraft to me but I see I can buy one for $130 online to install myself - there are lots of good reviews on the websites. Does anyone have personal experience with this witchcraft/snake oil? My gut tells me to stay away but part of me thinks for $130 and a new water heater every 5 years to give it a shot.

ClearWave HD-1 "Hard Water Conditioner" Clearwave Electronic Water Softener System: Kitchen & Dining