contamination, it is possible for the stored water to become contaminated especially if the tank is not sealed
or mixed with rain water.
Water Softener:
Water softening is generally used when the feed water hardness, iron or manganese
exceeds the feed water requirements for the RO system (outlined in Technical Overview Sec. II.). A
Reverse Osmosis System is much more efficient at removing salts such as sodium chloride, rather than
hardness (calcium carbonate). Hardness produces scale and this scale can block a membrane or increase
the rate at which the membranes need to be chemically treated with an acid for de-scaling. It is better to
have higher incoming salt rather than higher hardness. For this reason, a water softener is installed behind
an RO System.
Due to the flow rates of a water softener, it will generally need to be installed in the following order: Feed
Supply
Softener
Holding Tank
Pump
RO System
Use or further filtration.
Aeration/Filtration:
Given the correct water chemistry, levels or iron/manganese may be the only issue in
the water. This method is designed to remove these metals from the water without affecting the other
minerals in the water and without increasing the salt levels. The aeration/filtration will be set up in the same
configuration as the water softener.
Calcite Filter:
Reverse Osmosis will strip the minerals and salts from the water. The trade off is that the
water will then usually become ‘aggressive’ much like rain water. The pH will be low and the LSI of the
water will be low.
To use this water safely in a domestic setting, the pH and LSI will need to be balanced by using a Calcite
Filter. This will dissolve small amounts of calcium into the water to balance the pH and LSI. The most
common use of a calcite filter is in the following orientation: RO System
Tank
Calcite Filter
Standard Filtration (Big Blue)
UV
House
De-Ionising (Demineralising):
DI units are common as they are now required for medical sterilisation. DI
systems or housings are installed in the following configuration; RO System
Tank (If Applicable)
DI
Filter
Direct Point of use.
Installation Introduction
I. Site Preparation
When a suitable installation location is identified, you will need to determine if the system will be mounted
to a wall or free-standing. The System should ideally have both the water supply (feed water) &
Storage/Point of use within a 5m radius of the system to reduce negative effects on the pressure/flow and
performance of the system. It is also recommended that the process water (filtered water) does not have to
travel more than 2m elevation above the system. This will ensure that minimal backpressure is applied to
the pumps. Where possible, have the water running to a point lower than or at the level of the system for
best results.
Ensure that adequate space is allowed for to access all parts of the system and if mounted to a wall, the
fixings should be removable which can help maintenance.
II. Installation – Mounting
When mounting the system, you will need to position the system to the desired location and mark out the
mounting holes. NOTE: it can help to unscrew and remove the blue cannisters on the front of the unit to
reduce weight and gain better access to the mounting points to mark them.
III. Installation – Free-Standing
The frame of the unit is suitable to support the system if it is not mounted to a wall. You will need a firm
stable base such as concrete for the system to sit on. Where possible, it is best to fix the system to the
ground or adjacent structure that is already secured. This is to prevent the system tipping over and also to
prevent the system putting pressure on any of the plumbing connections.
