In hard water areas, limescale build up is a common phenomenon. It can create a fur deposit in plumbing or electrical appliances such as boilers, kettles, showers, washing machines and dishwashers. This build up can hamper the performance of the appliances, leading to frequent repairs and even equipment failure and permanent replacement. Limescale Inhibitors are used to inhibit the formation of limescaling. There are different types of limescale inhibitors: physical, chemical, electrolytic, magnetic and electronic. Electrolytic and Magnetic Inhibitors are quite popular among them. This article deals with electrolytic and magnetic scale inhibitors.
Table of Contents
What Is Limescale And What Are The Associated Problems That It Causes?
Before proceeding further, let us first see what limescaling is and how it affects the equipment.
As we are aware, limescaling is associated with water hardness. Hardness of water is due to the mineral content (mainly calcium and magnesium ions) in the water. If we try to understand in detail, it is the calcium carbonate in its calcite form which is the building block of limescale. High temperatures tend to alter the chemical equilibrium in the hard water, converting the soluble calcium bicarbonate to insoluble calcium carbonate, which then precipitates out of the water, bonding to the surfaces forming scale. As a result, it is actually the kettle, boiler, water heater and other heating equipment that are especially hampered by the effects of limescale formation. Limescale appears as a hard, chalky deposit and gets firmly bonded to the surface it rests on. With more and more deposition, it forms more thick layers. Limescaling can take up the color based on the contents present in hard water. For example, hard water with high iron content may create limecale which appears reddish brown in color.
Limescaling will obviously ruin the appearance of the fixtures. It also affects the heating elements, deteriorating the efficiency of these elements. This can lead to more energy consumption. As per research, for every 1mm of scale formed on a heating element, an extra 10% of energy is needed for it to function properly. As the build-up goes on accumulating, the heating elements become unusable, requiring replacement. This is why in hard water areas expensive pieces of equipment such as boilers break down regularly.
Limescale Prevention
Now let us see as to how we can tackle the problem of limescaling. The solution is to deal with the cause of the problem, which is to treat the minerals causing hardness. By using water softeners, the hardness causing minerals gets removed and hard water gets converted into soft water. This method can fully prevent limescaling. However, this can have some health implications as some of these minerals are good for human consumption. Also, there can be heavy expenses in terms of plumbing and other related aspects.
Another affordable method is to alter the way these hard water minerals behave and this is what water conditioner do. They reduce scale by preventing the hard water minerals from bonding normally. With the minerals being kept in the solution, you get health benefits the while tackling the negative aspects of scaling. Scale inhibitors also reduce scale formation. They are similar to water conditioners, but lack some of the key benefits that water conditioners offer like the ‘soft water lifestyle benefits’.
What Are Scale Inhibitors?
Now let us see what scale inhibitors are in general. They are compact devices designed to reduce the amount of limescale formed in hard water areas. They do this by changing the limescale makeup. Based on the type of limesclae inhibitor, they have agents that prevent limescale from easily attaching to the surfaces of fixtures especially when water is heated. This minimizes the damage caused water pipes, kettle, boilers, showers, and washing machines by lowering the level of deposits and also improving the water flow rate. All in all, this enhances the longevity of these appliances and also eases their cleaning process.
However, you need to keep in mind that limescale inhibitors never physically eliminate the calcium content in hard water. So limescale inhibitors may not be the go to solution for effectively preventing whole house limescale issues. It is the best solution for those who are not heavily troubled by limescale issues and are just in search of a solution to keep your fixtures work efficiently without spending much.
Now when dealing with limescale inhibitors, you need to be careful about the lifespan of the scale inhibitors. It is necessary to replace them periodically which ensure that your fixtures stay protected. The lifespan of these scale inhibitors vary from manufacturer to manufacturer and also depends on several other factors. The lifespan of most sale inhibitors vary from a year to about 10 years. Whatever be the manufacturer guaranteed lifespan, still based on the hard water concentration that you deal with in your area, you may need to get the change the scale inhibitor accordingly. For example, if water is exclusively hard (180 mg/L), then scale inhibitors need to be changed more often. You also need to look for properly approved models or else there is chance that the manufacturer warranty claims can get void.
Magnetic Vs. Electrolytic Scale Inhibitors
Magnetic and Electrolytic limescale inhibitors are two different types of scale inhibitors using different working mechanisms. We are trying to draw a comparison between these two based on some of the important factors.
Working
At first let us see what magnetic and electrolytic inhibitors are and how they work.
Magnetic Scale Inhibitors work by creating a tiny magnetic field which closely surrounds the water supply pipe. This leads to molecular changes in calcium salts present in hard water. The small magnetic field will change the irregularly shaped calcium crystals to regularly shaped calcium crystals. As a result, these crystals pass through the water without sticking to the fixture surfaces. If you invest in quality magnetic scale inhibitors which can produce effective magnetic field, then these types of scale inhibitors are found to be beneficial in inhibiting limescale formation. Magnetic scale inhibitors are usually affordable. However, invest in some cheap ceramic type magnets, and then they may not last longer, seeking replacement within a short duration of time.
Electrolytic limescale inhibitors work by forming an electrolytic current between the internal cathode and anode. This will result in charged zinc ions being dissolved in the water from the internal cathode. The dissolved iron particles will deter the limescale particles from coming together to create the fur deposits in the appliances. Thus they help in reducing limescale build up. They are usually priced higher than magnetic scale inhibitors.
Electrical Supply Requirement
Both electrolytic and magnetic scale inhibitors need not require an electrical supply or batteries.
Chemicals Involved
Both electrolytic and magnetic limescale inhibitors do not add any chemical in the water. Thus the water will be free of any pollutants.
Installation Procedure
Both electrolytic and magnetic scale inhibitors are usually available for installation in 15mm, 22mm or 28mm pipework. They can be purchased to be installed in line with the incoming water to individual appliances or even to the main household incoming water supply, protecting the whole household. Let us see the installation procedure of both of these scale inhibitors.
Magnetic Scale Inhibitors (15mm compression)
Positioning Instructions
- You need to ensure that the magnetic scale inhibitor unit is installed in such a location that it can be made readily accessible for examination, test, maintenance or even replacement.
- As the magnetic scale inhibitor unit is not directional, you may fit the scale inhibitor unit at any angle between horizontal and vertical.
- When choosing pipe, select a pipe run long enough to accommodate the magnetic scale inhibitor unit.
- It is recommended to fit the magnetic scale inhibitor unit on the cold feed approximately 1 metre from the appliance which needs to be protected.
- It is required to include an approved single check valve or any other no less effective back-flow prevention device at the point of connection between the supply and the magnetic scale inhibitor unit.
Connection
- For ensuring a leak proof installation, make sure that the pipe is cut square with a pipe-cutter. You need to do this even if the pipe run is initially broken into using a hacksaw.
- You can tighten the fittings with a 24mm spanner.
Electrolytic Scale Inhibitors (22mm compression)
Positioning Instructions
- For whole house protection, place the electrolytic scale inhibitor unit in such a location where it can be made readily accessible for examination, test, maintenance or even replacement.
- The electrolytic scale inhibitor unit can be fitted horizontally or vertically.
- You need to select a pipe run long enough to accommodate the electrolytic scale inhibitor unit.
- It is required to include an approved single check valve or any other no less effective back-flow prevention device at the point of connection between the supply and the magnetic scale inhibitor unit.
Connection
- For ensuring a leak proof installation, you need to ensure that the pipe is cut square with a pipe-cutter, even if the pipe run is initially broken into using a hacksaw.
- You can tighten the fittings with a 32 mm spanner.
Affordability
When considering the price point, magnetic limescale inhibitors are found to be more affordable than electrolytic limescale inhibitors.
Lifespan
Both types of inhibitor come with lifespan ranging from 1, 2, 5 or even 10 years. They need to be replaced after the specified lifespan.
Availability
During research, we have found limited options for both these scale inhibitors. The market seems to be flooded with more of electronic as well as chemical scale inhibitors.
Best Options of Magnetic and Electrolytic Scale Inhibitors
ProStream Magnetic Limescale Preventer

The magnetic limescale inhibitor contains powerful permanent magnets. It is easy to use without the need for any external power source. It works by allowing water to flow through an ultra-powerful focused flux magnetic field. This causes the minerals and other materials to get suspended in the water and they lose their ability to stick to things. It will take around two full days before the elements in the water start to regain their bonding ability. The magnetic limescale preventer reduces limescale buildup without the use of any chemicals. You need to simply clasp the Magnetic Blue Clasp onto your water pipe. There is no need for special tools. You also need not cut on water lines. The magnetic limescale preventer has a size of90mm x 60mm x 60mm. It will cost you around $25.
SESI Electrolytic Limescale Inhibitor

The electrolytic scale inhibitor is used for protecting hot water systems. The SESI is a cost-effective scale inhibitor solution which helps to tackle the limescale build up which could save on energy bills. It prevents limescale encrustation without adding any chemicals. For protecting the whole property, the unit should be installed in the rising main of the municipal water supply after the water meter and primary filter units (if any fitted). If used to protect a single appliance, then ensure that there is at least 3 metres of water pipe between the device and the appliance. 5 year guarantee is offered. It will cost you around $ 60.
Conclusion
In this article, we have seen how limescale is formed and how it affects the appliances. We have also seen methods to combat the situation. Scale Inhibitors reduce the limescale build up, but will never fully remove the limescaling. They use different mechanisms to tackle the problem of limecaling. Electrolytic scale inhibitors and Magnetic Scale inhibitors are 2 common types of scale inhibitors. We have tried to compare both these scale inhibitors. As seen, apart from the mechanism involved, the installation and lifespan of these inhibitors are quite similar. Also, magnetic scale inhibitors are more affordable compared to electrolytic scale inhibitors. Based on the budget and choice, you can invest in any of these inhibitors. However, remember that these scale inhibitors act by reducing the limescale build up. For effective removal of limescale build up, you may have to invest in water softeners.