Reverse Osmosis Information
Frequently Asked Question About Reverse Osmosis Systems:
Q. How does Reverse Osmosis (also referred to as “RO”) work?
A. RO works by passing water through a semi-permeable membrane that separates the pure water into one stream and the salt water into another stream. The process is called “Reverse Osmosis” because it requires pressure to force pure water across a membrane, leaving the impurities behind.
Q. What does GPD mean?
A. GPD refers to ‘Gallons Per Day”. This refers to the amount of pure water that is produced by the RO in a 24 period. For example, 22-33 GPD would mean the RO system produced 22 to 33 gallons of purified water per day. 24 GPD sounds like a lot of water, but actually that means 1 gallon per hour. So for example, the RO tank holds 2 to 3 gallons of water. If you used a couple of gallons of water at one time, it would take the RO one hour to refill the RO tank. So having an RO system that can produce 20 to 30 GPD is important, in order to have a system that is adequate for the typical family or homeowner.
Q. Why do they call it “Reverse Osmosis”?
A. In regular “Osmosis,” such as the process utilized by plants, water flows from a lower concentration of salts to higher concentrations. In “Reverse Osmosis,” the application of pressure greater than the osmotic pressure reverses the water flows from higher concentrations to much lower concentrations, producing pure water.
Q. Is this the best type of drinking water filter for my water?
A. This depends on the quality of the source water. Generally, if the water to be filtered is municipally-treated city water low in minerals, then less expensive carbon block filtration systems would be the best type. If the water is very high in minerals, then a reverse osmosis system or distiller that removes minerals, salts and chemicals may be desired.
Q. What do you mean when you say the water is “high in minerals”?
A. We mean that water that has a total dissolved solids (“TDS”) over 500 ppm or hardness over 200 ppm. However in some cases, even water that is lower than 500 ppm of total dissolved solids may need treatment by RO if there is some inorganic contaminant that needs to be removed. For instance, many customers are using an RO system who do not want to ingest the fluoride that is put into their water. Other contaminants that can be removed by RO include arsenic, or lead or other dissolved inorganic substances.
Q. How do I know what is in my drinking water?
A. If you are on city water, your local water must meet very strict Federal and State standards for purity. However, many areas use ground water (well water) high in minerals and salts. This can affect taste. All municipally treated water is chlorinated, and this can also affect taste and create odors in the water. If you are on a private well or spring, you should have your water tested.
Q. Will RO’ s remove hardness minerals or help cut down on scale build-up in coffee pots, etc.?
A. Yes! Most water contains “total dissolved solids” (TDS) , which is roughly the total inorganic mineral content of the water, and these are removed. The reverse osmosis membrane separates these dissolved solids, or salts and flushes them down the drain.
Q. Will these systems remove lead?
A. Yes. Both the RO membrane and the carbon block filter will reduce the lead. Carbon block filters use a lead-specific filter media combined with the carbon to reduce lead.
Q. Will these systems remove parasites or cysts?
A. Yes. The RO systems are certified for cyst removal.
Q. Is bacteria a problem with reverse osmosis systems?
A. Yes and no. We have tested many of our systems for total bacteria counts over the years and have not found higher levels after the systems unless the systems sat for several days in between uses. However, in some cases, particularly if the source water is high in bacteria and/or low in chlorine residual, bacteria can grow. We also have Ultra-Violet Sterilizer Systems that disinfect water after it leaves the filter system, insuring water low in bacteria. The manufacturers state in their warranty information that the RO systems are designed to be installed on water that is disinfected or does not have dangerous bacteria such as e.coli.
Q. Are RO systems difficult to install?
A. No. The RO systems come complete with all the tubing, fittings and items you need to install it. In some cases we may need to drill a new hole in your sink, or you can use an existing hole to install the RO faucet.
Q. How often should I change the filters in an RO system?
A. The filters should be changed once a year. The membrane should be changed every 3 to 5 years depending on the TDS levels in the purified water.
More information:
Water quality: How is RO water compared to bottled water?
Just as good or even better. We use the same technology, reverse osmosis (RO), as other major bottling plants use to filter water. Our drinking water has a refreshing taste with a touch of minerals —not like the flat taste of distilled or bottled water. The five-stage system is the most stable and complete RO process. The best part is that our system allows you to proactively monitor and maintain the unit’s performance and measure the purity of the water to ensure your family’s health yourself. That is something that you cannot do with bottled water.
Tap water safety: I thought my city’s tap water was safe to drink?
It is a known fact that many municipal water distribution channels across American cities are in desperate need of replacement from old age and wear. Water contamination can occur at almost any point in the delivery channel including lead leaching from corroded pipe solder, bacteria entering the system from water main breaks, or gardening chemicals back-siphoned from a careless neighbor.
Unfortunately most local and state governments do not have the financial resources to address these very expensive problems now or in the foreseeable future. To make matters worse, most cities also add chemicals like chlorine and fluoride to their water. The truth is, tap water quality in the US will most likely continue to decline in the coming years. The best way to protect your family from the increasingly wide range of contaminants found in today’s tap water is by installing a reverse osmosis drinking water system.
RO filtration: How effective is Reverse Osmosis filtration compared to other methods?
RO is the most convenient and effective method of water filtration. It filters water by squeezing water through a semi-permeable membrane, which is rated at 0.0001 micron (equals to 0.00000004 inch!). This is the technology used to make bottled water, it is also the only technology capable of desalinating sea water, making it into drinking water.
Non-RO water filters typically use a single activated carbon cartridge to treat water. They are much less effective, and the pore size on these filter media are much bigger, generally 0.5 – 10 micron. They can filter out coarse particles, sediments and elements only up to their micron rating. Anything finer and most dissolved substances cannot be filtered out. As a result, water is far less clean and safe compared to reverse osmosis filtration. Click for more detailed information on reverse osmosis technology.
Water Chemistry: Does the reverse osmosis process affect water pH?
In chemistry, pH is a measure of the acidity or basicity of a solution. We humans drink a variety of different beverages with varying pH ranges, from highly acidic orange and apple juice (3.3 pH), to mildly acidic milk and coffee (6 pH). Liquids that have a 7.0 pH are considered neutral and anything above that starts to become alkaline. Prior to any chemical reactions in the body, almost all drinks are naturally acidic. Water is an exception and can be both slightly acidic to mildly alkaline and drinking water ideally falls between a range of 6.5 to 8 pH.
Reverse osmosis filtration may or may not reduce the pH level of water at a noticeable amount. The pH difference after the RO depends on the composition of your input water source as well as the amount of gases such as CO2 in your local water supply. Water pH is actually a very complicated subject involving water and open air chemistry.
People that wish to increase the pH of their RO water can also easily add an optional calcite filter to increase the alkalinity of their drinking water.
Mineral Content: Is it beneficial to have minerals in drinking water?
This is actually the biggest myth in the water industry. To understand the issue clearly, first we need to examine “what minerals” are in our tap water. If we were to send a sample of water to a testing laboratory, we would get back a report that includes calcium, magnesium, and sodium along with a list of other minerals and contaminants. While some of these mineral are safe and benign, there are also many toxic ones on this list including fluoride, arsenic, chromium and radium just to name a few. Unfortunately there are no filtration systems available that can differentiate between good and bad minerals. Basic carbon filter systems will leave in all the minerals, including the highly toxic and radioactive ones. On the other hand, RO systems will remove 90-99% of these undesirable contaminants.
The truth is the majority of healthy minerals our bodies need come from the food we eat and not from drinking water. The main concern with water is actually over toxicity, not mineral content. Whether water contains 1 or 100ppm (parts per million) calcium isn’t really important, but the difference between 1 and 100ppm arsenic is of grave importance.
Membrane Maintenance: How much water is used to flush and clean the membrane?
Our reverse osmosis systems use premium TFC DOW Filmtec membranes which offer long lasting performance and reliability. These membranes use a process known as “crossflow” which allows the cartridge to continually clean itself during water filtration. It is this innovative feature that allows our membranes to routinely last from 4-7 years between replacements while still providing 90-99% rejection ratings to deliver exceptional value and performance. The water used to wash and treat the membrane is known as RO rinse water and is normally directed towards the drain. However many RO owners do reuse this water in their gardens, swimming pools, aquariums or for many other general household purposes. The rinse to product water ratio will vary depending on water conditions and the type of system, but normally falls between a 3:1 (undercounter) to 2:1 (countertop) ratio for open tank situations. For a small household, that is the equivalent of an extra 2-4 toilet flushes a day of used water.
