The most advanced choice in water filtration designed to remove the majority of all contaminants in your drinking water making it more pure than natural spring water at a tenth of the cost and available whenever you need it.
A convenient easy to install DIY unit, that is even more simple to service.
This 4 stage reverse osmosis system can be optioned to a 5 stage system if required. The filter unit can be installed vertically or horizontally virtually anywhere, under the sink, the house or the back of the cupboard. You only need to get to it once a year to change the filters.
The RO storage tank is available in various sizes to suit every application. The 8 litre storage tank comes standard with the unit providing approximately 6 litres of pure water. Options for larger sizes are available or smaller sizes upon request.
The storage tank can be installed upright or laid on its side in the cupboard, an adjoining cupboard, under the house or wherever you choose.
One of the features that sets the Aqua Safe ASRO4 System apart from other Reverse Osmosis Systems on the market is the design, we use 10mm tube and fittings instead of 6 mm used by others. This means the pure water comes out faster and the RO unit and tank can be installed away from the sink. Contact Aqua Safe if additional tube is required beyond the 1.5 metres supplied.
The ASRO4 System consists of:
Stage 1 - Sediment Pre-filter (part # AS2101S) to remove dust, rust and other suspended particles. Service life 2 years.
Stage 2 - Carbon filter (part # AS2001) to remove chlorine and chloramines from the water to protect the membrane. Service life – 1 year.
Stage 3 - Dow Filmtec US made TFC (Thin Film Composite) Ultrafine 200 litres per day RO membrane. Service life – 5+ years based on town water with annual cartridge changes. A water quality monitoring system with inbuilt alarm can be added as an option to let you know when the membrane needs to be replaced.
Stage 4 - Carbon filter – high quality 1 micron (part # AS2001) to remove any taste and odour leaving the water fresh and crisp to drink. Service life – 2 years in Aqua Safe’s scheduled service configuration.
The current running costs of the standard ASRO4 System are approximately $46.00/year for the carbon filter or $69.00/year when amortised with the sediment filter.
The system comes with 4 additional options.
The first enables you to exchange the 4th stage carbon filter for a pH balancing cartridge that will add trace zinc into the water and raise the pH up to between 7.0 – 7.3.
The second option allows you to turn the unit into a 5 stage Reverse Osmosis System by adding either a re-mineraliser cartridge or Pi filter, adding calcium and other minerals and raising the water pH up between 7.0 – 8.5.
The third option is to exchange the stage 2 carbon filter for a specialised carbon media cartridge for use in high hardness water where the total hardness is greater than 100ppm. This will treat the hardness and considerably increase the membrane life.
The fourth option is the addition of a water quality monitoring system that is mounted in the top cover to monitor the quality of the water coming from the membrane. The unit provides a visual display of the quality and will alarm when the water quality deteriorates to let you know when the system has a fault or the membrane needs to be replaced. (Unit runs for several years on long life batteries supplied.)
The fifth option is if you require Aqua Safe to install the unit for you for a low fixed cost.
Tap SelectionClick here to view our tap selection brochure, or alternatively click on the "Tap Selection" tab above.
Product BrochureClick the button below to view the product brochure.
Does low water pressure affect the quality of Reverse Osmosis water?
The performance & efficiency of a Reverse Osmosis (RO) system depends upon the membrane type, flow control, feed water quality (contaminants & quantity, pH, turbidity, total dissolved solids; TDS), pressure & temperature.
RO systems require a reasonably high pressure in order to function properly. Most domestic RO systems require 400kPa (60 psi) to operate efficiently and maintain performance. A minimum operating pressure of 350kPa is recommended however the units will operate down to 240kPa although this will affect the quality of water produced. If the water pressure is too low the RO will not be able to overcome osmotic pressure (the bonding between water molecules and the dissolved impurities). The higher the contaminant or TDS level, the higher the osmotic pressure. If the water pressure is too low the treated water production will be less efficient and the contaminant rejection rates much lower resulting in poor quality treated water.
A boost pump can be added to an RO system to increase the pressure and improve the quality and quantity of water produced.
Bench top RO systems are able to operate at lower pressures than under bench systems due to the fact that they do not have to work against back pressure created in the storage tank as it fills with water and compresses the air in the tank.
How long does it take to install an ASRO4 system?
It takes approximately 2.0 to 2.5 hours to install the ASRO4 system including flushing the cartridges ready for use.
Could you please advise the bench hole size required for the tap displayed on this drinking water system?
The tap hole size is the same for all systems. A 10-12mm hole is required.
How do you switch between running water from the tap and from the spout?
The diverter valve that connects to the tap switches between the tap and spout when required.
What is the Water Quality Monitoring System?
This can be added as an option to the Reverse Osmosis system to indicate when the membrane or drainage line has blocked or failed so the membrane can be replaced and the high water quality maintained. Without this you are unable to tell when the membrane has failed or the unit is not operating correctly unless you test the water coming from the membrane with a TDS meter. A handheld TDS meter will test it at that point in time although you will need to disconnect tubing to get a reading from the membrane outlet rather than from the system as this will be after another carbon filter, pH balancing filter, re-mineraliser or Pi filter.
The water quality monitoring system displays the quality at the push of a button and monitors the membrane output 24 hours 7 days a week from day 1. It will also alarm you when the quality goes out of specification giving you peace of mind that you are always drinking purified water.
The ASRO4R system also has the option of a flow meter as the resin filter only treats a certain volume of water before it needs to be changed. This meter indicates the remaining volume left with filter and alarms when the volume of water has been treated. The filter can then be changed and the flow meter reset.
How often will I need to change the filters for the ASR04 system and the ASBTRO4 bench top system? How much will both of these options cost?
The filters in our reverse osmosis ASRO4 (underbench) system have an effective life of 12 months and the replacement cost is $92 ($46 AS2001-carbon + $46 AS2101S sediment) although the sediment can be replaced every second year.
The filters in our reverse osmosis ASBTRO4 (benchtop) system have an effective life of 12 months and the replacement cost is $99.00 ($49 sediment,part # 17420 + $49 carbon, part # 17679). These are high quality K series Omnipure Cartridges. Prices effective August 2016. Check replacement cartridges for current pricing.
What is Chloramine and how do you remove it from drinking water?Chloramines Removal
Chloramine is now becoming a common disinfectant for drinking water supplies replacing Chlorine in many capital cities including Sydney, Melbourne and Brisbane. This rollout will continue in the future with more and more towns and cities moving to this form of disinfectant. The main reason for this is the considerably reduced level of carcinogenic by-product trihalomethanes (THM’s) formed when using chloramines and it stays in the water much longer, a much higher residual.
The most common form is Monochloramine with concentrations ranging from 1.5 to 2.5 mg/L. Typical residual in Australia is 0.5 mg/L with a maximum of 3 mg/L. It is less effective than chlorine and therefore needs a higher initial dose and longer contact time. Unlike chlorine, monochloramines do not add any taste or smell to the water.
Types of Chloramine
There are 3 forms of inorganic Chloramine; monochloramine, dichloramine and trichloramine. All of these can be formed when water containing or injected with ammonia is chlorinated. The pH and the ammonia/ chlorine ratio determine which kind of chloramines is formed. At a pH <3 mainly trichloramine is formed, at pH 4-7 mainly dichloramines is formed while at a neutral pH >7 or above monochloramine is the main form produced.
The ammonia component of chloramines is also different depending upon the pH of the water. At pH levels >7 ammonium hydroxide is formed, <7, ammonium ion is formed. The ammonium ion is readily removed by cation resin (softener resin) or mixed bed resin however water hardness can substantially affect this. Ammonia is removed preferentially to sodium by cation resin but is displaced by calcium and magnesium (water hardness). Therefore a resin filter will remove ammonia initially but will then release the ammonia when it becomes exhausted with hardness. This could lead to an ammonia spike in the treated water.
Due to the low molecular weight, chloramines and in particular monochloramines are difficult to remove from water by reverse osmosis (RO), distillation, water softeners or resin filters. Distillation or evaporation does not remove chloramines effectively as the chloramines are volatilized and carried over to the product water (distillate). Pre-treatment is required for RO systems to remove chloramines prior to reaching the membrane with specialised carbon filters.
Standard activated carbon (GAC), carbon block or enhanced carbon filters do not remove chloramines. The carbon in these types of filters, whether it be coal, coconut shell or wood based carbon does not absorb chloramines. It removes or reduces them to some degree through a reduction-reaction, its ability to act as a catalyst for the chemical decomposition or conversion of chloramines to chloride (salt) in water. This reaction converts the chloramines into chloride salt and ammonia. This reaction releases the ammonia allowing it to pass through RO membranes and other filters excluding resin. The ability of resin to remove it is dependent upon the pH and other contaminants in the water. The free ammonia can also come in contact with other contaminants in the water and form undesirable Nitrates and Nitrites.
Granular activated carbon (GAC) filters can be used to remove/ convert chloramines however long contact times and low flow rates are required to achieve >95% removal. The cartridge rated capacity will also need to be reduced to 12-25% of the rated chlorine removal capacity for chloramines removal. This is dependent upon the cartridge manufacturer, type of GAC etc. Standard carbon block filters have very low removal/ conversion rates and are not recommended. These filters will not remove the ammonia from the water. For this reason we do not recommend the use of these carbon filters and suggest the use of chloramines reduction cartridges for cities such as Sydney, Melbourne and Brisbane where chloramines are currently used.
Potassium or sodium metabisulphite can also be used for chloramines removal.
Chloramines Reduction Filters
Specialised Chloramines reduction cartridges are manufactured specifically to remove chloramines and ammonia in one. They use a specially developed catalytic carbon to absorb and bond the chloramines. These cartridges need to be installed before or in place of any other carbon cartridges to be effective.
The main manufactures of these filters are; Omnipure Chloramine Reduction, Pentek Chlor Plus, and Filtrex Chloraguard. These are all high quality US made cartridges with a proven track record and available specification sheets.
Do Reverse Osmosis systems remove essential minerals from drinking water?
A common misconception is that drinking water is an important source of essential minerals for the human body. While many minerals such as calcium, magnesium and sodium can be obtained from drinking water, research has shown that mineral uptake from tap water is very low. An adult can generally fulfil between 5-20% of their recommended daily intake of selected essential minerals by drinking tap water
This is provided they drink 2 litres of tap water per day and that the tap water has a relatively high mineral content. Most cities in Australia have low mineral content, partially due to the water source and the water treatment process; making it unlikely to even achieve these levels. Bear in mind there are only a select few minerals contained in tap water, while a great many are required, and essential for the basic functions of the human body to complete.
The main source for these essential minerals is from the food we eat, not from the water we drink. A balanced diet is the best method to providing all of the minerals our bodies require.
Why do Reverse Osmosis systems have wastewater?
Part of the water that flows into a reverse osmosis (RO) system flows through the membrane and comes out as treated water. The rest is used to wash away the rejected contaminants down the drain as waste.
If not properly designed, RO systems can use large quantities of water to produce little treated water or use small quantities of water and produce low quality treated water while shortening the membrane life. Most domestic RO systems are designed for a 20-30% recovery up to 50% recovery, i.e. 2-5 litres of water produced for every 10 litres of water used. This can also be expressed as a ratio of 1:4 down to 1:1. Higher recovery rates can be obtained but doing so will shorten the membrane life.
RO membranes are easily fouled if contaminants or concentrated impurities are not washed away quickly enough. The higher the contaminant or TDS level the lower the recovery rate of treated water or the more wastewater required.
Can Water Filters Remove Fluoride?
Fluoride is injected into drinking water supplies at various locations around Australia in the form of sodium silicofluoride and sodium hexafluorosilicic. As per drinking water standards this is put into the water at up to 1.5 ppm (parts per million) although the average is 1.0 ppm with possible short (a few minutes or hours) spikes over this due to equipment malfunction or human error. These short term spikes will have little effect on the capacity of fluoride removal filters.
Standard carbon filters of any type are unable to remove fluoride without the addition of special media and even when this media added, they will only remove up to 40%. To remove higher percentages requires reverse osmosis, distillation, resin, alumina or bone char.
Reverse osmosis (ie. Aqua Safe ASRO4) removes approximately 96% and requires resin post cartridges to achieve >99.99% reduction. Distillation removes a higher than 96% but is a batch process and is not considered user friendly and therefore not very popular anymore.
Alumina based systems (ie. Aqua Safe AS280) remove approximately 93% of fluoride but are not suitable for use in bench top systems or incorrectly designed under bench systems as very small trace amounts can under some circumstances leach into the water requiring removal with an additional specialised filter
Bone Char made from animal bones has been used for industrial water treatment for many years although the vast majority is not approved for drinking water treatment. Drinking water certified NSF61 granular bone char is available however, contact time with the media is very important for removal making cartridge design critical for performance. Removal rates tend to vary considerably and multiple (4 cartridges/stages) filters will be required to remove approximately 95%.
Reverse Osmosis is the recommended system for fluoride reduction/removal followed by correctly designed alumina and bone char systems. For reduction levels above 99%, we suggest specialised resin deioniser cartridges installed after a reverse osmosis or alumina system. This type of system may then also include a pH balancing and re-mineraliser cartridge to increase the water pH and add minerals back resulting in a 6 stage water filtration system.
What is Fluoride?
The majority of fluoride is either a by-product of aluminium production or artificially produced. It is sold to government and councils around the world saving companies millions of dollar in disposal costs. This chemical is injected into town water supplies to reduce the incidence of tooth decay in children. Many studies have been undertaken over the last 50 years to prove or disprove the effectiveness of the product in preventing tooth decay. From the evidence available there appears to be as many studies concluding the benefits of its use as there are those concluding the dangers and ineffectiveness of the product.
The fluoride used in town water is either a by-product or artificial and man made as opposed to natural fluoride found in rocks and soil. Artificial fluoride is a different product altogether. It is an extremely corrosive dangerous chemical. While many dentist support its use there is an ever growing group of those who don’t.
Fluoride is currently included in just about all available toothpastes. Many countries and towns that have been putting fluoride into their water supplies for many years are now discontinuing this.
The Nazis under Hitler used fluoridation during WWII to reduce the resistance of the masses to domination, control and loss of liberty. The Russians have also used fluoride/fluoridation in the past for the same reason.
There are maximum levels set for the dosing of fluoride into town water supplies, however the chemical has a different weight and density to that of water and can therefore accumulate in water mains overnight or during the day. Water then used from these mains can have higher levels of fluoride.
High levels of fluoride can cause fluoridosis or tooth decay. Fluoride and Fluoridation has also been said to cause cancer based on studies carried out in America in 1980.
Consumers need to make up their own mind as to whether they want to leave it in their drinking water or remove it although it is a difficult chemical to remove and requires specialised filters or reverse osmosis systems.
What are the water pressure gauges for?
A water pressure gauge is installed on each Reverse Osmosis unit to confirm the unit is operating and running correctly with the required minimum pressure. They will also help determine if the sediment and carbon pre-filters are blocked and need replacement. A second pressure gauge can be fitted to the under bench units to let you know when the pre-filters are blocked while a third gauge can be added to show the storage tank pressure as this will need to be adjusted after a few years.
What is Reverse Osmosis?
This water purification process has gained in popularity over the last 20 years since it was first used commercially in 1968. It is used extensively for purifying sea water and uses membrane (a thin film or skin through which water molecules can pass) technology.
The easiest way to explain reverse osmosis is by firstly explaining osmosis.
Osmosis is the movement of a low concentration solution through a semi permeable membrane into a high concentration solution such as sea water or contaminated water.
In reverse osmosis, the idea is to use the membrane to act like an extremely fine filter to create drinking water from contaminated water. Pressure is applied to the contaminated water, reversing the osmotic process and forcing water molecules through the membrane.
Reverse osmosis membranes don’t allow particles or molecules larger than 0.0005 microns to pass through to the other side of the membrane. Essentially only water (H20) passes through while other contaminants, bacteria, viruses, chemicals and other dissolved substances are flushed to drain.
As a size comparison against 0.0005 microns; a human hair is 100 microns, the smallest particle visible to the human eye is 50 microns, the smallest bacteria is 0.2 microns and the smallest virus is 0.002 microns.
Reverse Osmosis membranes are manufactured with different pore sizes and support structures and from different materials. Membrane pore sizes can vary from 0.0001 microns to 5 microns depending upon the type and purpose.
Sea water or Desal membranes are constructed to operate at very high pressures up to 7,000 kpa with small pores that reject in excess of 99% of salt at loading greater than 32,000 mg/l.
Brackish/Salt contaminated water membranes operate at high pressures around 1,500 kpa and have larger pores to reject in excess of 99% of salt at loadings greater than 2,000 mg/l.
Lower pressure/low energy membranes are designed to operate between 400 and 1500 kpa with more open larger pores designed to reject 99% of salt at loading around 500 mg/l for ground water and municipal supplies.
There are two main types of reverse osmosis membranes commonly used in home reverse osmosis filter systems:
- Thin Film Composite (TFC)
- Cellulose Triacetate (CTA)
TFC membranes have considerably higher rejection rates; and filter out more contaminants than CTA membranes. However they are more susceptible to degradation by chlorine and other oxidants and need to be protected from them by pre-filters.
These membranes are made by forming a thin, dense contaminant rejecting surface film on top of a porous substructure. The materials of construction and the manufacturing process for these two layers can be different and altered for the desired combination of pure water produced versus contaminants rejected. The pure water production and contaminant rejection characteristics are predominantly determined by the thin surface layer which thickness ranges from 0.01 to 0.1 micrometres.
Several types of TFC membranes have been developed including aromatic polyamide, alkyl-aryl poly urea/polyimide and polyfurane cyanurate. Polyimide membranes are highly susceptible to degradation by oxidants such as chlorine and chloramine. These must be removed to prevent damage and destruction of the membrane.
These membranes were developed along with the first reverse osmosis systems in the late 1950’s. They are composed of a thin dense surface layer (0.2 to 0.5 micrometres) and a thick porous sub-structure. Contaminant rejection is undertaken by the thin dense layer with the sub-structure providing structural support. They are relatively inexpensive to manufacture and hence are cheaper to buy than TFC membranes.
CTA membranes also have a low rejection of organic contaminants, low pH tolerance but a high tolerance to oxidants such as chlorine.
The chemical 1,4 dioxane is used to create the membrane porosity features. This chemical causes cancer with some traces of it left after manufacturer requiring considerable flushing before use.
The removal of inorganic contaminants by reverse osmosis membranes is complex and is dependent upon the interactions and mixture of irons in the feed water. Ionic contaminants are more readily rejected than neutral ones and polyvalent ions are rejected to a greater extent the monovalent ions. If the polyvalent ion is strongly hydrated, rejection is even higher.
As electrical neutrality must be preserved, ions diffuse across the membrane as a cation-anion pair. As a consequence, rejection of a particular ion depends on the rejection of its counter ion. An example of this is with sodium; sodium sulfate has a higher rejection than sodium chloride because the divalent sulfate ion is rejected to a greater extent than the monovalent chloride ion.
pH variations also affect the rejection characteristics of the membrane depending upon membrane composition and ion type. For example, fluoride rejection increases from 45% to over 90% as pH increases from 5.2 and 7.2 whereas nitrate rejection decreases slightly as pH increases from 5.2 to 7.0.
A large number of councils are now using chloramine to treat drinking water supplies instead of chlorine. This chloramine contains ammonium ions which are poorly removed by activated carbon causing dramatically reduced rejection rates and degradation of the membrane. The variability of local water conditions and sources also varies the performance of the membrane although a Total Dissolved Solids (TDS) monitor will show the current performance of the unit. Specific ion rejection performance can however only be determined by selected testing. As a general guide reverse osmosis membranes are more effective in rejecting ions or organic solubles with molecular weights greater than 200 however carbon filters before and after the membrane can greatly affect the contaminants rejected or absorbed thereby affecting the overall performance of the system. The larger the pre-carbon filter ie 12” in the Aqua Safe ASRO4 unit the greater the chloramine and contaminant removal.
While membranes are successful at removing bacteria and viruses the systems can be contaminated from the product water side colonizing the tape tubes and storage tank. Regular disinfection (every 6-12 months) is necessary to maintain the water quality. This can generally be done by the system owners at very low expense or carried out by service technicians.
Do Reverse Osmosis filters remove everything from the water?
The simple answer is, No they don’t. Reverse osmosis systems filter down to 0.0005 microns, however many contaminants are smaller than this or are forced through the membrane due to design constraints or poor design. Some contaminants are removed by as much as 99% while many others are removed by only 30-50%. This can be seen by looking at membrane rejection tables.
The average contaminant removal by reverse osmosis filter systems is approximately 85%. This will vary depending upon the quality and number of contaminants in the water supply and the system design.
The performance of a reverse osmosis system can be checked by using a TDS (Total Dissolved Solids) meter and should be between 7-10ppm.
To remove more contaminants an additional filtration stage is required. This involves one or more mixed bed DI resin filters that further purify the water removing 99.99% of contaminants. This Ultrapure water can be provided by the Aqua Safe ASRO4R system.
How pure (in parts per million) can your RO systems produce?
This depends upon the quality of the incoming water supply but generally sits between 2 & 7ppm with the standard RO system. The ASRO4R produces higher quality water and therefore lower TDS.
Buy with Confidence
Aqua Safe is proud to provide free delivery to anywhere in Australia for orders over $55.00. Deliveries are sent either by Australia Post or by Courier depending on where you live. All online orders are fast tracked through our warehouse for quick dispatch.
10 Year Warranty
Aqua Safe International warrants all residential water filtration systems to the original purchaser for a period of ten (10) years starting from the date of purchase provided the warranty is registered with Aqua Safe customer care.
This warranty covers defects in materials, components and workmanship and includes pressure limiting valves, connection fittings and isolation valves. Excluded are filter cartridges, inline filters, membranes, UV lamps, quartz lens and UV ballast.
Commercial water filtration systems are covered for a period of five (5) years to the original purchaser starting from the date of purchase provided the warranty is registered with Aqua Safe customer care.
This is a long standing warranty policy first implemented by the company in January 2005. Prior to this date all systems were covered by a 3 year warranty.
30 day "No Questions Asked" Satisfaction Guarantee
We offer a 30 day Unique "No Questions Asked" Satisfaction Guarantee on all new standard* residential water filtration systems.
If at any time during the first 30 days (starting from the date you receive the item) you are not 100% satisfied with the quality or performance of your filtration system, simply re-package the unit and send it back to us in "as new condition" (used or unused) with a copy of the tax invoice and we will issue a full refund for the purchase price (excluding any installation costs if installed by Aqua Safe).
This allows our customers to purchase virtually risk free 24/7. Non-stock items or special order items are also excluded.
* Standard systems only. System with added options are excluded.
Watermark Approved Products
All Aqua Safe products are Watermark approved.