Rv Water Softener

Try a little borax in the tank. I use 1/4 cup every couple of tank fills. If your using campground water try Home Depot for a softener/filter cartridge. Attach to hose intake.
Both have worked for me.

we like Soft water also, so I bought a "waterstick" water softener. It is a conventional resin based softener reasonably compact. Takes about 15 minutes to recharge with table salt. The downside is capacity, less than the ones CW etc. sell, but the price is right, and it is also available in a version that will remove some iron. We've had ours now for almost 3 years and it's perfect for us. In places with really hard water we can get a weeks worth of use out of it.

It's capacity if about 1500grains, which is less than the bigger units but still good for about 100 gallons up to 500 gallons of water depending on hardness.
www.watersticks.com

They often have them posted on ebay as well.

The Essential RV 16,000 Water Softener completely softened water that was off the charts in hardness. I use a dual-stage carbon/Sediment filter before and after the Essential RV filter and it seems to make the softener last longer before having to recharge it with salt. I can tell you the motorhome H2o tastes terrific so now we don't have to waste money on water bottles at the store anymore. Also, soap lathers more effectively, don't have to use as much, and my skin feels softer. A huge benefit is our motorhomes pipes, washing machine, and hot water heater are not getting plugged with calcium buildup. There are so many positives with this RV water softener that I can't recommend it enough!