Nelsen Scale Prevention Systems  utilize Filtersorb SP filter media to first remove already existing scale from pipes and heat exchanger surfaces and then to further protect the system from future formation of scale. Filtersorb SP is based on a process that changes the chemical structure of scale-forming minerals. This technology is so effective that it requires a contact time of only seconds. Filtersorp SP works well in front of RO membranes, which it keeps from clogging with calcium carbonate. A preexisting membrane’s efficiency is improved after only 10 days if calcium carbonate was the reason for the blockage.