How is the capacity of a water softening system calculated

Table of Contents

• What is the importance of capacity?
• What happens when the capacity is "empty"?
• What does the capacity depend on?
• How exactly is the capacity calculated now?
• What does the capacity say?
• Isn't there an easier way?

Click here to go directly to the calculator: To the capacity calculator for water softening systems

What is the importance of capacity?

In the context of water softening, you can imagine the capacity as the capacity of a smartphone battery. Every water softening system that works with the ion exchange process has a certain capacity. The capacity depends on the size of the tank or the amount of exchange resin in the tank.

What happens when the capacity is "empty"?

If the capacity is exhausted, the system must go into regeneration. This means that the system flushes itself with salt brine. We have put together how this works in the section How a water softening system works.

What does the capacity depend on?

The capacity is given in the unit m³ x °dH (cubic meters times degrees German hardness). It depends on two factors:

• Water consumption
• Water hardness

The higher the water hardness and the higher the water consumption, the higher the capacity must be.

How exactly is the capacity calculated now?

The calculation differs between basic and duplex systems in the safety factor. The safety factor ensures that the systems do not regenerate too often or too rarely, so that the systems are regularly flushed.

• BASIC systems: Capacity = daily water consumption in m³ x water hardness in °dH x 3
• DUPLEX systems: Capacity = daily water consumption in m³ x water hardness in °dH x 2

What does the capacity say?

For example, if a decalcification system has a capacity of 20 m³ x °dH, then in other words this means that the system can deliver 20 cubic metres of water for each degree of hardness removed (°dH). With a water hardness of 20 °dH, this would then be one cubic metre of soft water (until the regeneration break).

Water quantity in m³ = capacity in m³ x °dH / water hardness in °dH

Isn't there an easier way?

Of course, you don't have to use your calculator now, but you can calculate the capacity using our calculator. This will suggest the right system for you. Go to the capacity calculator for water softening systems