FilterSorb SP3 Advanced Salt-Free Scale Prevention Units

FilterSorb NAC (“Nuclear Assisted Crystallization”) technology is the leading rival of OneFlow TAC (“Template Assisted Crystallization”). The two competing technologies both have many strong points and we have chosen to offer both rather than choose between them. Either FilterSorb, priced below, or OneFlow, will do an excellent job of salt-free scale prevention.

FilterSorb is NSF 61 certified. It adds no chemicals to the water, needs no regeneration, needs no electricity or drain connection. It is trouble free, and the expected media life is three to five years. FilterSorb not only prevents formation of hard water scaling, it also helps to reduce previously formed scale. FilterSorb does not add sodium to water and it does not remove calcium and magnesium from drinking water. It does not alter pH or total dissolved solids of the treated water.

Here’s how one author explains the NAC process:

The Filtersorb SP3 acts as a catalyst by accelerating the transformation of the calcium and magnesium minerals into harmless “Nano” particles. When the inlet water goes into the water conditioner tank, the up flow pulls the water through the fluidized Filtersorb SP3 media which then acts as a catalyst and pulls the hardness minerals of calcium and magnesium out of the solution and then transforms these minerals into inactive Nano crystal particles. Because the hardness minerals have been transformed into Nano particles, these Nanoscopic particles make their way through plumbing systems without attaching on to pipes, fixtures, valves, or heating elements. Filtersorb SP3 is also a maintenance free system that does not require cost for salt, costs for water or for regeneration material.

Because of the simple in/out design without electrical or drain connection, FilterSorb units are especially easy to install. We highly recommend installing a sediment filter in front of the Filtersorb system to guard against intrusion of particulate.


Basic Filtersorb Unit with Optional Bypass (red-handled valves). In this upflow system, water flows upward from the bottom of the tank through the treatment media.  No backwashing is required, so, unlike conventional water softeners, the Filtersorb system does not require water for backwash, rinse, or brine circulation.

FilterSorb units are made with only a few liters of high potency media in a large tank, so there is virtually no pressure drop. The larger-than-necessary tank enhances performance by allowing the Filtersorb media to fluidize freely and have more contact time with the water.

FilterSorb can be used in water temperatures from 38 to 140 F and up to a hardness of 75 grains, although sizing for the residential units offered on this page is for water up to 25 grains hardness. If your hardness exceeds 25 grains, please call for sizing advice.

FilterSorb can tolerate high salinity (up to >2000 grains). Acceptable pH range is 6.5 to 9.5. Maximum iron content recommended is 0.2 ppm, and maximum manganese 0.5 ppm. Up to 1.3 ppm copper can be tolerated, but the medium requires zero oil, phosphates, and hydrogen sulfide. Although Filtersorb is fairly chlorine tolerant, the life of the media will be prolonged if a carbon filter is installed in front of the scale prevention unit in city water or chlorinated well water applications.

Standard Filtersorb Treatment Unit with the optional bypass. No electricity or salt are needed. The standard Filtersorb unit is built in a Vortech mineral tank with an upflow Clack head.

Pure Water Products FilterSorb Prices for Residential Units

Free Shipping to Lower 48 US Addresses.


GPM Rating


Filtersorb 8 X 44 with 3 liters of Filtersorb.




Filtersorb 9 X 48 with 4 liters of Filtersorb




Filtersorb 10 X 54 with 5 liters of Filtersorb




There is an optional bypass valve sold with the unit for $37.

For information,  see our commercial page.