I have tried several ideas that never worked well, including magnets, electromagnetic frequencies, etc. So, I ended up with a "standard" water softner that uses salt. I purchased it off the web, it's designed to be portable, and it uses standard table salt for regeneration. The specs say it can soften 800 gallons before regeneration, and that's a lot of water. I like the fact it uses one container of table salt for regeneration because the salt is sold in every market around. Regeneration is super easy - pour the salt into the unit, wait 30 minutes, rinse salt solution into the drain, hook it back up, and you're done.