Water Softeners

The Alpine Pure Water softener has a number of components.

1) Auto Regeneration Head that measures the volume of water used and calculates when the Softener Resin requires regeneration.

2) Softener Resin, is in the pressure tank and the water flows through to soften the water.

3) Media Pressure Tank, contains the Softener Resin and has the auto regeneration head on top.

4) Brine Tank, is connected by a tube to The Regeneration Head which fills it with the required amount of water to make the brine then sucks the brine out when required for regeneration of Softener Media.

5) Salt, added by you to the brine tank as required.

What it does:

The water softening process is accomplished by a chemical ion exchange that replaces the “hardness ions” which are mainly calcium and magnesium in your water with an equivalent number of sodium or potassium ions.

During the softening process your household water passes through the Softener Resin and the magnesium and calcium contained in the water is removed. The Softener Resin attracts the minerals in the water like a magnet

When most of the sodium and potassium ions from the Softener Resin have been exchanged with the calcium and magnesium ions from the water the Softener Resin needs to be recharged with brine from the brine tank.

Alpine Pure Water Softeners are demand based (after a certain number of cubic meters have been processed) regeneration happens in the early hours (2am) in the morning.

It goes through several cycles which are basically:

Back Wash: The resin pressure tank is flushed with the water to waste with the flow in the opposite direction to service.

Brine Rinse: The brine is sucked up into the pressure tank to rinse the resin. It will remove the calcium/iron/manganese in the resin that has been removed from the water in the past service cycle.

Slow Rinse: The resin is rinsed and the excess brine and the remainder of the hardness is rinsed out of the resin during this cycle.

Brine Refill: Water is passed to the brine tank from the Auto regeneration head.

Brining: This water is left in the tank to mix with the salt to form brine for the next regeneration.

Fast Rinse: The resin is fast rinsed to compact the resin remove the residues of calcium, magnesium and iron deposits to waste.

Service: This means that the water softener is serving soft water for the house.

The different sized media tanks contain different volumes of Softener Resin and by calculating the amount of water you use you determine the size of the softener.

Each tank size or Resin Volume has a fixed capacity to remove hardness before it needs to be regenerated by washing the softener resin with a salt brine during regeneration. This brings the softener resin to full capacity in order to continue to provide softened water.

The normal recommendation is that the softener has the capacity that regeneration takes place once every four to seven days.

Calculate Your Water Softener Size:

Before you can calculate your water softener size you need to have a water test done to determine the parts per million (ppm) of hardness in your water.

To calculate your tank size you need to know your service flow rate which is the volume of water you use over a 10 minute period. Determine which water fixtures and appliances may be running for more than 10 minutes at the same time. This may be early in the morning when your family is getting ready for work or school.

You need to consider how often you have visitors and calculate water usage increases.

Your flow rate needs to be considered to provide the water with sufficient time in contact with the softener resin media to allow the system to do its work and operate at the maximum efficiency. For example 1 cubic foot of resin can only have a flow rate of up to 27 LPM otherwise the water will not be in contact with the resin for long enough to remove all hardness.

Some also look at Peak flow but a system that handles your service flow easily will also handle increased peak flows.

Water Usage Flow Rates:

Taps 9.5-11 ltrs per min

Toilets 8-10 ltrs per min

Baths 15-20 ltrs per min

Showers 9.5-18 ltrs per min

Dishwasher 7-11 ltrs per min

Washing machine 9.5-11 ltrs per min

Total Water Flow Used Over 10 Minutes = _________

Alpine Pure 940 Water Softener max flow rate is 27 ltrs per min

Alpine Pure 1054 Water Softener max flow rate is 40 ltrs per min

Alpine Pure 1252 Water Softener max flow rate is 54 ltrs per min

Next we need to decide how much water you use per day:

The average person uses between 150 – 300 litres of water per day.

multiply this by the number of people living in the house.

multiply this by mg/l of CaCo3 hardness from your water test.

multiply by four - seven  days to regeneration) to get the water softener capacity needed.


200 ltrs per person per day x 2 people = 400 ltrs (water test is 120 ppm)

400 x 120 = 48000 x 7 days = 336000 ppm + 20 % reserve = 403200 ppm

If you regenerated every 6 days = 288000 ppm + 20% reserve 345000 ppm

so a 1 cubic foot 940 Water Softener is ample providing service flow is 27 ltrs or less

One cubic foot of resin has the ability to remove 500000-550000 mg/l CaCo3 of hardness from your water but there is better salt efficiency if it is kept between 3500000- 40000 mg/l CaCo3 of hardness.

Do not run the resin to exhaustion. The water softener should have a reserve capacity of 20 to 25% before it regenerates.

This means that it regenerates when the softener resin are 75 to 80% saturated with the hardness ions.

A system that is larger is better than smaller but do not go to big as the softener resin can become compacted and channeling can happen if you don't regenerate often enough.

Water softeners can remove a limited amount of dissolved Iron from your water, however if you have over 1-2 ppm, then an Iron reduction system using Filox™ would be recommended.