A Softener with a timer that regenerates even if you are not using it is a bad idea for septic systems. Imagine all the water running through your septic treatment system that is unnecessary with a softener that is not of the demand type. A demand type softener regenerates only when it is needed based on your family’s usage. You should upgrade your system if you have an old timer type control head on a septic system. Check out this web site for answers to your septic questions. http://www.septicprotector.com They suggest using a separate septic system built just for your softener. The alternative to a softener would be some of the newer technologies I don’t have any tried and true answers for you when it comes to new technology. Softeners have been around for quite some time and I know of nothing used more or that works as well for the application of removing hardness. There are products that will reduce scale buildup but these products are not classified as water softeners.
Respectfully David Walling