RO – FAQ
1. What is reverse osmosis (RO)?
Reverse osmosis, or RO for short, is a sophisticated water purification process that was originally designed by the U.S. Navy to provide drinking water to submarine crews from seawater. It works by forcing pressurized water through minuscule pores of a semi-permeable membrane, effectively filtering out impurities. To produce great-tasting and highly purified water in our homes today, modern RO units incorporate cutting-edge carbon and mechanical filtration technologies with this membrane filtration method.
2. How does it work?
To understand how it functions, let’s break down the process. First and foremost, the water in modern home systems is propelled by normal city water pressure and runs through a sediment pre-filter that removes any dirt and small particles present in the water. Following this, an organic contaminants-absorbing multi-stage pre-filter filters out chlorine along with its by-products. This treated water then enters what is called a membrane – which is essentially a very tight, sheet-like filter – which allows pure water to pass through but rejects dissolved solids as well as impurities such as lead, arsenic, and sodium. Furthermore, to cleanse the surface of the membrane itself, some of the incoming water is used before being drained out via pipes beneath your sink (kitchen drainpipes). The clean purified drinking water generated by our unit gets stored in a small tank until needed. Finally, when you open your faucet attached to our system placed over your sink; this purified drinking water flows through another carbon filter which polishes it further making it ready for safe consumption. However, there are additional instruments that contribute significantly to ensure purification quality such as flow control devices and check valves among others together play an important role that goes beyond just the filtration mechanism alone- but we’ll save those details for another day.
3. What is the best RO system?
When it comes to choosing the best RO system, it’s important to consider the features that each model offers. While all RO membranes produce highly purified water, not all systems are created equal. For example, the F5 is perfect for city water applications and boasts a Seven-stage filtration process that removes even the smallest of contaminants. The F5 considers water conservation with a high-efficiency design that produces more water in less time while using less water than traditional RO systems. And for consumers looking for a low-maintenance premium system, the F5 offers a Stainless steel designer faucet, Lead-free stainless-steel storage tank. When it comes to choosing the best RO system, there is no one-size-fits-all solution- but by taking into account your unique needs and preferences you can find one that works perfectly for you.
4. Is an RO unit like a distiller?
When considering whether to use an RO unit or a distiller for water treatment, it’s important to understand their differences. While both methods are effective at reducing the amount of dissolved solids in water, they utilize distinct processes. Specifically, RO filtration works by using a tightly-woven semi-permeable membrane, whereas a distiller functions like a large kettle that boils water and collects the resulting steam. Carbon filtration is essential for both methods to remove chemicals. It should be noted that low-cost distillers often lack carbon filters and may not provide adequate results.
5. Is distilled water purer than RO water?
When it comes to determining which type of water is purer, there are some differences between distilled water and reverse osmosis (RO) water. Distillers tend to remove slightly more mineral constituents, such as sodium, but may not be as efficient when it comes to eliminating volatile chemicals like chloramines. Many cities have started using these disinfectants instead of chlorine, and they can be difficult for distillers to remove completely. On the other hand, RO with carbon filtration does an excellent job of removing evidence of chloramines. It’s important to note that without proper carbon filtration before distillation, any volatile chemicals will end up in either the air or your distilled water. Despite these differences in approach, both methods produce highly pure water.
6. Do RO units waste a lot of water?
The amount of water that an RO (reverse osmosis) unit uses can be a point of concern. In reality, the answer to this question is contextual. An RO unit utilizes water during its cleaning cycle and eliminates impurities, which is consistent with how most water-based appliances work. When you compare it to other daily activities such as washing dishes or clothes, flushing toilets, or hosing your car down, an RO unit consumes more water than you drink. However, once the storage tank has filled up, the unit disengages, and pipes no longer flow—all in all, it’s equivalent to adding two or three toilet flushes a day to your general usage.
7. What are the yearly expenses for maintenance?
pre and post-filters need to be changed annually to make sure they are functioning correctly. the rate of filter changes will depend on the quality of the water and the usage. the yearly cost is less than $0.40 per day, depending on the point-of-use RO model. The RO membrane usually lasts for two to five years.
8. What is the importance of water pressure for an RO system?
It is essential. The water pressure forces the water through the membrane to clean and wash away the solids. Low water pressure reduces production and premature fouling of the membrane. The ideal pressure to use an RO system is 60 PSI. Pressure below 0 PSI is generally considered insufficient and must be raised with a booster pump.
9. Can I connect the RO unit to a refrigerator/ice maker?
Yes, but only if you have 1/4 ” pipe access to the under-sink RO unit. Some refrigerators measure pressure, so you should check with the manufacturer. The pressure of the RO unit is about 2/3 of the inlet pressure.
10. How long does the RO unit last?
Almost forever if you maintain it regularly and replace wearing parts like the storage tank and mixer. The typical life of the membrane is about 2-5 years, depending on the quality of the treated water.
11. Does RO remove chlorine?
Although the RO membrane itself does not remove chlorine, it does not have to. A pair of quality carbon filters will do the job. If the first carbon filter does not remove all the chlorine, the membrane would quickly eat away.
12. Do RO units remove minerals important to health?
RO units remove approximately 95% of the mineral content, but the issue of minerals is probably the most controversial in drinking water treatment. Experts on both sides speak convincingly. As long as the water tastes good, it is within the body’s acceptable range. The main problem with water is chemicals, not minerals. Whether water contains 30 parts per million or 3 parts per million of calcium is not nearly as important as the difference between 0.5 parts per million and 5 parts per million of chloroform.
13. Do RO units need electricity?
No, they work with water pressure. You only need electricity if you add an electric booster pump or an ultraviolet lamp. Standard devices have neither.
14. Why are RO units so popular?
Because they produce great tasting, ultra-pure water at a reasonable price compared to buying bottled water, and they start up fully automatically with no problems. Dedicated water drinkers know that not all water tastes the same.
15. Can a water softener harm RO?
No, a water softener can help extend the life of your RO membrane. Calcium and magnesium (limestone) are the two hardest minerals for an RO membrane to remove, and sodium (which is added to the water using a water softener) is much easier on the membrane because it repels 98% of the sodium in the water.
16. How many and what type of sites could be affected by PFAS?
Because PFAS have been used in a wide variety of applications over time and they do not fully break down naturally, they are present in low levels almost everywhere in the environment. Increased levels of PFAS can be found near sewage treatment plants, landfills, and places where fire-fighting foams have been used (e.g. mining operations, fuel refineries and storage facilities, airports, fire-training grounds and transport infrastructure). Consequently, these chemicals are found in many places and are not just limited to Commonwealth-owned sites.
The Department of Defence has a comprehensive PFAS Investigation and Management Program underway, which has identified around 27 Defence sites that are now either undergoing investigations or have reached the stage of determining management options. Airservices Australia’s National PFAS Management Program is also conducting assessments of sites where it has provided aviation fire and rescue services.
The Department of Infrastructure, Transport, Regional Development, Communications and the Arts is undertaking the Australian Government’s $130.5 million PFAS Airports Investigation Program at airports where the Commonwealth historically provided firefighting services using PFAS-containing foams.
State and territory governments are conducting their own investigations of state-owned sites. For example, fire fighters may have used fire-fighting foams containing PFAS at training sites. Visit our PFAS Advice page for information about PFAS activities in your jurisdiction.
17. What does it mean if I live in a PFAS contaminated area?
The Australian Government is working closely with affected communities to help them understand what PFAS contamination means for them and their daily lives.
Advice on reducing exposure to PFAS will vary with each location due to local circumstances so community members should follow the most current advice provided by the investigating agency’s human health risk assessment and state or territory advice for their local area. People wanting to discuss personal health issues should talk to their local GP.
18. What about future contamination by PFAS?
Since 2002, the Australian Government Australian Industrial Chemicals Introduction Scheme (formally NICNAS) has published a number of alerts on PFAS. AICIS has recommended that:
- PFOS, PFOA and other related chemicals should continue to be restricted to essential uses where less hazardous alternatives are not available.
- PFOS-based fire-fighting foam should only be used in essential applications (i.e. not be used for training purposes).
- Industry should actively seek alternatives to and phase out PFAS and PFAS-related substances of concern.
- Existing stocks of PFAS fire-fighting foams should be disposed of responsibly on expiry.
- Importers and users of PFAS should be aware of international activities relating to PFAS.
- Importers should ensure that alternative chemicals are less toxic and not persistent in the environment.
- Up-to-date information on safe use of PFAS and handling should be provided on labels and Safety Data Sheets.
A large body of work is underway across Australia – both to manage existing contamination and to increase our ability to prevent further contamination from PFAS and other industrial chemicals of concern.
19. How are people exposed to PFAS?
Most people living in Australia will have detectable levels of PFAS in their blood. Exposure to PFAS can be from a variety of sources such as food packaging, non-stick cookware and stain protection applications for fabrics and carpets.
There are a number of specific sites across Australia, where concentrated releases of PFAS have resulted in increased levels of PFAS in surrounding soil, water and produce. Visit our PFAS Advice page for links to identified investigations areas near you.
For most people in PFAS affected areas, the highest risk of exposure is likely to be through the consumption of contaminated groundwater (i.e. bore water) and food grown using contaminated ground water.
Outside of the identified investigation areas, unless you live near industrial areas, landfill sites, or firefighting training grounds where PFAS-containing foams were used, it is unlikely that increased levels of PFAS would be present in your local environment.
The Department of Health has produced a factsheet on exposure pathways: