The tank & softener are all in one, very compact & easy to replace the softener pellets. My Dr. told me I needed to get a new moisturizer as my skin was super dry. I told him "Santa Clause was bringing me a new water softener for Christmas" and OMG, what a gift!! Costs nothing to run, only need to fill it twice a year, depending on usage of course, has removed the hard water scum from my dishes, my clothes and - most of all - ME. I LUV it, thank you GE for making such a super great, economical unit that even a retired grandma can afford.