You can use potassium chloride in a water softener system instead of salt. I have a reverse osmosis system from Culligan for drinking water (it's the best as far as waste water is concerned.... 1 gallon RO water to 1 gallon waste). Before you buy a RO unit, CHECK THE WASTE RATIO!! I'd purchased a different kind earlier and found that for every gallon of good water it was washing 8 gallons of water down the drain! The water softener system I have is also from Culligan but don't buy the potassium from them... go to Home Depot and you'll save about $6/bag. Potassium is *supposed* to be safe for your animals to drink and safe for your plants but I used it to water the plants and they started looking really bad. I started saving rain water and using RO water when we didn't have enough rain and they perked back up. Either way, with salt or potassium I wouldn't drink it or give it to my animals. Too much potassium is just as bad as not enough.. the same with salt.