Arrange Visit

Free advice in the convenience of your home.

Quick Quote

Expert impartial advice provided.


Water treatment terminology, common terms in the water softener industry.


A solution of salt used for regenerating the water softener resin.

Brine Tank

A separate housing where brine, or salty water, is stored.

Brine Line

A tube that allows brine to flow into the softener for regeneration, and to the brine tank when it is not required.

Bypass Valves

A set of 3 valves that isolate the softener from the mains water supply.

Cation Exchange

The ion exchange that happens in the resin, whereby your resin is regenerated.

Check Valve

A code of practice requirement, this valve ensures one way flow to your softener, not soft water to the mains water supply.

Control Head

The mechanical valve in the softener that diverts water for the regeneration process.

Counter current Regeneration

A regeneration process where the water flows backwards through the softener, it can enhance salt efficiency.

Degrees Clark

A measurement of water hardness.


The point where brine and rinse water is carried away from a water softener.

Drinking Tap

A separate hard water outlet, usually found in a kitchen.

Dry Salt Storage

Salt tanks that have water added during the regeneration process. At other times the tank is dry.


Alternative term for a tap.


The quantity of water running through a water softener (often measured in cubic metres per hour).

Grains Hardness

A measure of water hardness.


The combined measured total of calcium and magnesium in water (measured in mg/l) as calcium carbonate.

Hard Water

Water containing more than 20 mg/l of calcium carbonate.

Hold Over Period

Time between the need for the softener to regenerate and the actual start of the process.


Connection of a water softener to the mains supply, and the installation also of bypass and check valves.

Ion Exchange

Where unwanted ions are transferred to the resin in the softener, and wanted ions are left in the water supply.

Meter Controlled Softeners

A softener where the regeneration of the softener is directly linked to the capacity of the resin bed.


A safety outlet fitted to all water softeners. It carries away water in the unlikely event of a malfunction.

People Days

Term used to clarify the capacity of water softeners. A 10 people day softener can supply one person for 10 days, or 10 persons for 1 day.

Pressure Drop

A decrease in water pressure between the softener inlet and outlet connections.

Pressure Limiting Valve

A valve to bring down water pressure through a series of pre-determined stages and pressures.

Pressure (Resin) Vessel

The container for the ion exchange resin, distributors etc.

Proportional Brining

A fairly new method to proportion the amount of brine added during the regeneration process – there are two types, Infinite and Graduated.


The process of refreshing or renewing the resin for the ion exchange in the water softener.


The process of refreshing or renewing the resin for the ion exchange in the water softener.

Regeneration Level

The amount of salt per litre of resin required to regenerate on an ion exchange bed.

Reserve Capacity

A reserve of resin set aside for use during the hold over period. Both the reserve and hold over are features of time clock controlled systems.


The synthetic material used to enable the ion exchange process. It looks a bit like brown sugar and the beads range in size, up to a diameter of 1.3 mm. Smaller uniform sizes can make the softening process more effective some studies have concluded.


Also referred to as Sodium Chloride. It is required to ‘carry’ the sodium that facilitates the ion exchange process. It is available in granules, powder, tablets or pellets. Ask your supplier for further details.

Salt Efficiency

A measure of how well a softener performs in terms of salt usage.

Salt Storage

The maximum amount of salt that can be fitted into a softener, often measured in kilograms.

Sensor Controlled Softeners

Similar in advantages to a meter controlled softener. It uses a probe to constantly look at the condition of the resin bed, regeneration is started as and when required.

Soft Water

Water containing less than 20mg/l of hardness as measured in CaCO3 (see explanation also of Hard Water).

Softened Water Brining

A softener of high quality output that uses softened rather than hard water to make up the brine solution. It improves both capacity and salt consumption.

Softening Capacity

This term refers to the hardness removing capability of a softener between regenerations. It is related to the amount of salt used, it is usually measured in litres per minute.


Water supply isolation valve usually sited at the boundary to a property.

Stop valve

The internal supply valve that turns water on and off in a property, usually at the point of entry into the building.

Time-clock Controlled Softener

A softener that regenerates at a pre-set time, based upon an estimated usage. It is programmed in manually, and can be reset if it is not as efficient as it could be.

Water Pressure

A term that refers to the pressure of water related to the limitations of a water softener. Too low pressures may require a separate pump to be installed.

Water Supply

The supply of mains water from either a municipal or private water supply.

  • Which
  • Checkatrade