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Electric and Magnetic Water Filters Information

Water filtrationElectric and magnetic water filters use electrical and magnetic fields and energy to treat water and wastewater. The electric treatment of water forces oppositely-charged ions to move in opposite directions. This produces collisions, which result in the formation of microscopic nuclei. In turn, these nuclei cause calcium carbonate to precipitate within the water. Electromagnetic treatment passes water through a variable magnetic field. The field changes the electrical properties of water and dissociates agglomerations or clusters of water molecules. In this way, both electric and electromagnetic wastewater and water treatment equipment can be used to improve the solute capacity of water.


Here are some facts from basic chemistry about solutions. Substances, or solutes, that are truly dissolved into a solvent cannot be filtered out by any conventional mechanical methods. This is because the solute is broken down to its molecular level in the solvent. Take the classic NaCl, or common table salt, dissolved in water as an example. As the solute, or the salt, dissolves in water, the water solvent breaks the salt down into positive smaller Na+ sodium ions and much larger Cl- chlorine ions. The non-metallic ions tend to be larger because they have all their outer shell electrons plus more while the metallic ones lose all their outer shell electrons. But those differences in size are irrelevant since both ions are many orders of magnitude too small to be caught by a filter that would also let the water molecule pass through. Even organic compounds, like sugars and certain alcohols, dissolve down to their molecular level, except their molecules stay together. Those molecules don’t break apart like inorganic salts that dissociate into separate ions.


Simple electric filters just use DC-powered static charge electric fields to attract ions: positive ions to the negative plates and vice versa. Usually the positive ions have the metal in them such as Na+. They are used extensively in hard water home water systems to cause the scale to precipitate out in a safe place and keep the rest of the system, like the valves and hot water heater, from filling up with mineral scale. Another variation of this system is to have sacrificial anode, or its positive pole, of a light metal like aluminum or zinc and a cathode of a heavier, stable metal like copper. The anode will decay and the metal will bond with the larger, negative non-metallic ion, and that new salt compound will not be water soluble. So the inorganic compounds will precipitate out of the solution and can be trapped by a filter. The only big issue is that the anode needs to be replaced and the cathode needs to be cleaned regularly. Similar systems are used for rust protection in cars since they use just a small amount of low voltage DC current.

The main use for these electric and magnetic water filters is in conditioning hard water to use in a home’s water system, in mainly home well-based water systems, or in areas where the municipal water is hard. The phrase hard water originated when water from some sources required more soap to produce suds than water from other sources. Waters that required more soap were considered “harder” to use for cleaning. The molecules that make water hard are different from most aqueous solutions in that its solubility decreases with higher temperatures. So hot water pipes and the water heater are prime areas of scale buildup because the crystals come out of the solution faster in the hotter water.


Water hardness is a measure of its dissolved mineral content. As water seeps through the ground, it contacts minerals such as limestone and dolomite. Under certain conditions, small amounts of these minerals dissolve into the ground water and the water will become “hard.” Water hardness is measured by the concentration of dissolved minerals. The most common hardness minerals are carbonates and sulfates of magnesium and calcium (MgSO4, CaSO4, MgCO3, CaCO3). Water with a total hardness mineral concentration of less than about 17 parts per million, or ppm, is categorized as “soft water” by the Water Quality Association. “Moderately hard” water has a concentration of 60 to 120 ppm. “Very hard” water exceeds 180 ppm.

Generally, electromagnetic water treatment employs an external solenoid coil through which alternating or pulsed currents are passed. This process creates an electromagnetic field in the water system, which forces scaling calcium ions to form inert non-scaling crystals of calcium carbonate to safely wash through the system. They also change the shape of the crystals from dendritic like to blob like. The electromagnetic frequency field uses the conductivity of the water to extend protection throughout the entire circulation system. So instead of the minerals attaching themselves to the pipes, valves, or water heater, they are passed through the system. So these systems really don’t filter the water, since they don’t remove anything. The water still has the same hardness and minerals as it had coming out of the well. But these filters help save the plumbing by reducing the hard water scaling.


One of the main uses for magnetic water filters is in industrial machining applications. It usually involves filtering the cooling water streams that are used to cool molds or sensitive machine tool parts. The filters attract the small metallic chips out of the cooling stream, preventing them from contaminating the items being cooled. Similar filters are used in various lubricant applications, like automatic transmissions, but those applications are oil based, not water based.

Some wastewater treatment systems apply an electric treatment to purify water or wastewater. Typically, a municipal wastewater treatment system uses a multi-stage process, mostly mechanical and chemical, to renovate wastewater before it is reused. A wastewater treatment system also removes organic matter, solids, nutrients, disease-causing organisms, and other pollutants from wastewater using traditional non-electro-magnetic methods. Since these electro-magnetic filters, at best, just mitigate scale buildup of otherwise natural and harmless minerals, they don’t seem to have any real use for municipal wastewater treatment where bacteria, micro-organisms, and particles in simple suspension mixtures are the main issues. Sure, super high frequency electro-magnetic radiation, like microwaves, and visible or ultra violet light can disinfect, but they are not part of these sorts of filters. They have frequencies many orders of magnitude higher than these electromagnets. Part of wastewater treatment is to let the dehydrated sludge sit in the sun.  

The main cases where electro-magnetic filters are used in wastewater treatment are special industrial cases where soluble harmful metal salts can be targeted for precipitation by replacing the cation, or the salt’s negative non-metallic ion, with one that will cause the metal to precipitate as insoluble metal by sacrificing a relatively harmless metal in a sacrificial electric anode. Or the metals can be recovered by having a magnetic field of the right frequency and strength to help separate out the heavier metallic compounds in the waste stream mixture. Or, in some cases, magnetic or iron powder is added to the waste stream to bond with the desired substances to be removed. Then, later downstream, the new magnetic or ferrous compound can get separated out by magnetic fields.

There is an element of anti-science and fraud in the field of electro-magnetic filtering. There have been many real scams, mainly in the home water system conditioning business, but not limited to that market. It can be certainly said that electro-magnetic filtering hasn’t lived up to the claims made, but there are some real, if not limited, advantages. But these sorts of filtration systems do nothing to combat micro-organisms and most organic compounds that are the main threats to human health. At best, they help prevent hard water scaling in plumbing systems and filter out some heavy metals in specialized industrial applications. So one must be wary of extravagant claims by the manufacturers and read up on appropriate research that is scientifically valid.



ResearchGate—Electromagnetic Fields for the Treatments of Wastewater: A Review of Applications and Future Opportunities

Science and Education Publishing—Study of Electromagnetic Waves on Industrial Waste Water

Google—Treatment of Water with Static and Radio Frequency Electromagnetic Fields

Water Softener Critic—Eddy Electric Water Descaler (Magnetic System)—2016 Review

H20dotcon—Water-Related Pseudoscience, Fantasy, and Quakery

PennState Extension—Magnetic Water Treatment Devices

CSI—Magnetic Water and Fuel Treatment: Myth, Magic, or Mainstream Science?

Current World Environment—Magnetic Water Treatment in Environmental Management: A Review of Recent Advances and Future Perspectives

Smartflow—Ferrogard Magnetic Water Filter

Related Information

CR4 Community—Anyone Have Success With a Magnetic Water Softener?

CR4 Community—Treatment of Drinking Water

IEEE Spectrum—Eight Technologies for Drinkable Seawater

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Proaudio55 / CC BY-SA 3.0



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