Working on a 10 y/o system, the tech seamed reasonably knowledgeable and able to rebuild two calcite tanks to make the system operational, but could have done a more professional job when reassembling the calcite tank valve body--like cleaning and lubrication. Also, the tech who initially assessed my needs should have asked about our water condition to better update our system to current conditions--suggest we install a different mineral tank valve body program disk. Lastly, they were very expensive, in my estimation. I spend $1,800 for something I could have done myself. Of course they did in three hours what would have taken me eight.