Pure Aqua, Inc. designs and manufactures water treatment systems in addition to multi-media and activated carbon filtration package. This package was created for a customer in Jordan in February 2013. There is a prechlorination prior to the multi-media filtration and activated carbon filtration. Both of these filtrations are set up to backwash when there is sufficient pressure drop. For more information click here: http://www.pureaqua.com/water-filters.html