I have a water softener. when I Installed it I found the water hardness was at 15 gpg. When I called the city they said between 20-27. so I set the softener to 30. I have always suspected it wasn't doing much, but we do go through salt (very slowly). so I had the water tested, and it says its 280 (z) which from what I've read is hard. why is the softner not softening? I double checked that it wasn't set to bypass... when I run the water in the house I see the softener showing water is going through...