Water softening

Hard water has a notoriously bad reputation. From causing scale buildup in your kettle and soap scum rings around your sink to shielding your hair from hydration and irritating your skin, dealing with the symptoms of hard water can be expensive, frustrating and tiring. But it doesn’t have to be. Let us introduce you to water softeners.

Calcium and magnesium ions. Illustration.

First things first, what is hard water?

Water hardness refers to the mineral content of your water, specifically the concentration of calcium ions (Ca2+) and/or magnesium ions (Mg2+) present in your supply.

Arched arrow pointing left to the water hardness scale. Illustration.

The water hardness scale

The water hardness scale. Water with calcium/magnesium concentrations over 200 mg/l may experience problems with scale. Illustration.

Water hardness exists on a spectrum, with soft water containing low concentrations of dissolved calcium and/or magnesium, and hard water containing high concentrations of these minerals.

The impact of location

While Scotland is renowned for having soft water, especially in comparison to its English counterparts, it’s a common misconception that all water in Scotland is naturally softer. Water hardness is highly dependent on the geological environment surrounding the water source, as the neighbouring rocks and sediment will impact the type and concentration of chemicals that dissolve into the water.

Why is hard water a problem?

Shower head with visible scale damage. Illustration.

Damaged appliances

The most common problem associated with hard water is the white, chalk-like scale (often referred to as limescale) that can build up on any surfaces routinely exposed to water, such as shower heads, kettles, taps, boilers, cookware and washing machines. Scale buildup is particularly problematic because it can drastically reduce equipment performance while also creating an ideal environment for bacteria to grow, and severely degrading the aesthetic appearance of your appliances. While alternatives to softeners are readily available, they often fail to address the root of the problem, only adding to the expense of upkeep. Plus, you still need to pay out for a replacement when your appliances and fixtures prematurely deteriorate.

Severe scale buildup inside a pipe highlighting a considerable loss in internal capacity of the pipe. Illustration.

Clogged pipework

Over time, a dense layer of scale buildup can form around the inner walls of your pipework, significantly reducing the capacity for water flow or - in severe cases - blocking pipes entirely. In these instances, the affected pipework may require total replacement which can be a costly and tedious process.

As the speed of scale formation accelerates when water is heated, central heating systems are often the worst affected by scale. Since scale buildup acts as insulation inside the pipes, it keeps the heat in which in turn heavily reduces boiler efficiency while driving energy costs up.

Bird’s-eye view of someone washing their hands without any soap lather. Illustration.

Soap that lacks lather

A nice soapy lather is near impossible to create with hard water, unless you’re willing to use a bucket load of soap to make it happen. The high calcium and magnesium content in hard water impedes the ability of soaps and detergents to properly dissolve, and worse still, it can often leave an insoluble soap scum residue that clings to skin, surfaces, dishes and laundry. Not only can it leave things feeling unclean, but the soap scum can create new environments for bacteria to grow.

Row of three hair products labelled ‘colour rescue’, ‘clarifying shampoo’ and ‘hydrating conditioner’. Illustration.

Brittle hair

The minerals in hard water can inhibit the ability of your hair to absorb water and moisture, coating the hair strands in a film that acts as a barrier to the hydration your hair needs to stay healthy. As the calcium and magnesium build up, hair can begin to feel dehydrated, brittle and dull. Some experience issues with product buildup in their roots, a dry scalp, difficulty with styling or lifeless colour. Clarifying shampoos offer a wash-to-wash solution but adds another step to your hair care routine without preventing the problem itself.

Row of three skin products labelled ‘cooling serum’, ‘gentle face cleanser’ and ‘pore cleansing face mask’. Illustration.

Irritated skin

The high mineral content in hard water alters how soaps and cleansing products break down during use, ultimately impacting how they work on the skin. Firstly, more product is required to activate the ingredients, for example to produce a lathering effect once applied. The use of more product can lead to increased sensitivity, while the interference of calcium and magnesium can impact the products ability to penetrate and hydrate the skin as intended. Secondly, a soap-scum residue can form when the product and water react, making it difficult to work the product into the skin and rinse it off thoroughly. This can lead to clogged pores from leftover product or irritation from excessive rubbing of the skin during product removal.

Cup of tea with an obvious layer of scum on top. Illustration.

A bad cup of tea?

The perfect cup of tea is a heavily debated topic; what goes first, the tea bag or the milk? At what point do you add the sugar? And, how much milk is too much milk? While it seems there’s no right answer, an oily film glaze and some white particulate floating on the surface don’t usually crop up in the discussions.

While harmless to health, hard water can not only create a layer of scum on top of your tea (alongside foam, bubbles and/or white particulate), but alter the taste and texture of the drink. While this isn’t the be all and end all for some, it can be the final straw for others.

If these problems are sounding familiar, get in touch and we can discuss your options.

Sodium ions. Illustration.

What is water softening?

Water softening is the process of removing the calcium and magnesium ions from the water, typically substituting the calcium and magnesium ions with sodium ions (Na+) in a process known as ion exchange. Aptly named, a water softener is the piece of water filtration equipment used to reduce water hardness.

How does a water softener work?

Water softener and brine bucket diagram. Illustration.

The unit

Water softening takes place inside a water softening unit; a vessel filled with a sodium rich resin that replaces the calcium and magnesium ions with sodium ions (or, occasionally, potassium ions) as the water filters through the unit.

The process

As the resin is continuously swapping out calcium and magnesium ions for sodium ions, eventually the sodium ions will require replenishment. This replenishment is automatically built into the water softener's design in the form of a brine bucket which is located externally, next to the vessel.

The automated settings

The water enters through the inlet valve at the top of the unit, passes through the resin as it travels down to the bottom of the vessel, and finally exits through the riser tube at the centre of the unit.

Brine bucket diagram next to a bag of salt. Illustration.

The importance of salt

The brine bucket contains a dissolved salt solution which, once instructed by the control valve on the water softener, will flush through the resin, regenerating the sodium ions whilst flushing the calcium and magnesium ions out of the unit. In terms of maintenance, it’s important that the brine bucket is regularly topped up with salt (the bucket should always be at least half full) to ensure that the solution has enough sodium ions to completely recharge the resin.

A portion of a large filtration system showing a sediment filter housing, water softener, brine tank and pressure vessel.

There are a large selection of water softeners to choose from, ranging in size, valve control options and resin. Water softeners should work with the other elements in your water filtration system while supporting the desired flow rate and pressure of your supply. If you’re not sure where to start, we’re here to take out the guesswork.

What are the benefits of a water softener?

Regardless of the make and model, water softeners are often an uncomplicated and valuable addition to any water filtration system.

A pile of three bags of salt. Illustration.

Low maintenance

Routine media regeneration and internal cleaning, which can include rinsing and backwashing cycles, are handled automatically by the water softener. The control valve at the top of the unit ensures that cleaning is scheduled for preferred times and between selected intervals.

The only maintenance external to this is the task of periodically topping-up the brine bucket with salt. The bucket should always be at least half full to ensure that the salt has enough contact time with the water to create a solution with a high sodium concentration. When topping up the salt, it’s good to check that the salt hasn’t compacted at the bottom of the brine bucket and that the lid is securely in place.

10+. Illustration.

Long-lasting

We’ve had many water softener units that last over a decade with the same resin that they started with. Regular maintenance, for the unit as well as the system as a whole, ensures that the softener can offer great value for money.

Aside from the durability of the unit itself, a water softener has the power to prolong the lifespan of pipework, appliances and water based equipment by removing the scale-causing minerals. This reduces the cost of purchasing descaling products, replacement parts and new appliances when the existing ones prematurely breakdown.

Star medal. Illustration.

Reliable and effective

Quite simply, it does what it says on the *vessel*. 

Water softeners have a reputation for being both reliable and effective, with a high rate of success. Of course, the success of your water softener will rely on the health of your water system as a whole, but they’re easy to look after and relatively self-sustaining. An annual service to make sure everything is in order is all that is recommended for these units.

Most impressively, water softeners are so good at what they do that they can start to reverse some of the scale buildup from pipework and appliances. Similarly to rain collecting minerals from the rocks in the ground, the softened water can start to absorb some of the minerals back into the water from scale in the system, reducing the accumulated buildup.

Water filtration system comprising of a water softener, brine tank, pressure vessel, two sediment filters and a UV unit.

Sound like the solution you’re looking for?

Large water filtration system including a water softener and a circular brine tank.
Dropper adding blue liquid to a water testing pot.
Hands opening a white box with piled bags of salt in the background.
Piece of pipe with a thick layer of scale buildup reducing its internal diameter.