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If you’re looking for a water purifier that will provide outstanding drinking water for your home or business, Reverse Osmosis (RO) filtration is one of the most popular and best water filtration methods available.
Below you will find diagrams, charts and explanations to answers your questions about RO systems. If you have other questions which are not answered here, please visit our our main water education page or Contact Us.
If you're searching for a water filtration system that will give you outstanding water...
Here are a few reasons to consider RO:
RO filtration improves taste, odor and appearance of water by removing contaminants that cause taste and odor problems.
RO systems have very few moving or replaceable parts make RO systems easy to clean and service.
With an RO system, you can cancel your water delivery service and stop purchasing cases of bottled water. Reverse Osmosis filtration provides “better-than-bottled water” quality water for just pennies per gallon.
RO systems remove pollutants from water including nitrates, pesticides, sulfates, fluoride, bacteria, pharmaceuticals, arsenic and much more. An RO systems’ carbon filter will also remove chlorine and chloramines.
Reverse Osmosis filtration is the perfect solution if you’re looking to improve the taste, odor and appearance of your water. Here are some of the most common applications for RO technology:
Installed at the kitchen sink: A small RO filtration system can be installed at the kitchen tap to provide top-quality drinking water. This is called a “point of use” (POU) water filtration system and can also connect to your fridge and ice machine. Water pressure is a consideration with some refrigerators, so be sure to refer to your RO system’s owner’s manual as the pressure from the Reverse Osmosis unit is about two-thirds of the incoming line pressure.
Whole-house RO system: A whole-house Reverse Osmosis system (also called a POE “point of entry” system) allows you to have filtered water at all sinks, showers and appliances throughout the house. A POE system ties into the main water line coming into your home and is generally installed in the garage. This type may not always be an available option due to the upfront cost of such a large filtration system, as well as requiring more long-term maintenance and service.
Reverse Osmosis is a process in which dissolved inorganic solids (such as salts) are removed from a solution (such as water). This is accomplished by household water pressure pushing the tap water through a semipermeable membrane.
When household water pressure pushes water through the RO membrane and additional filters, such as sediment or carbon filters, the impurities are filtered out and subsequently flushed down the drain. What is left, is delicious, clean-tasting drinking water. Note that many RO units incorporate a 4-5 stage process for optimal water quality.
You may be interested to know that Reverse Osmosis technology is not new. In fact, RO processes began being utilized by municipalities back in 1977. Since then, Reverse Osmosis has become increasingly popular because it is safe, cost-effective, and easy to maintain.
Generally, residential "Point Of Use" POU RO systems are installed and stored under the kitchen sink. Regarding the common components of a four to five-stage RO system, note that:
Diagram of a Reverse Osmosis System with Basic Components:
At ESP Water Products, we’ve been selling water filtration equipment for 25+ years. This longevity in the industry has made us very selective in what we sell and endorse. We carry only RO systems that have won our confidence--those that are manufactured with the highest-quality components, offer outstanding warranties, and have the highest ratings for customer satisfaction.
Public water suppliers work hard to provide clean water for their customers. The problem is that there are many contaminants, especially those that cause taste and odor issues, which are simply not EPA regulated. These contaminants can easily penetrate aquifers, streams and rivers, bringing impurities straight to your water lines.
That’s where Reverse Osmosis comes in. With a Reverse Osmosis filtration system, you can filter out impurities and produce outstanding drinking water for your home or business.
Reverse Osmosis (RO) is a water treatment process that removes contaminants from water by using pressure to force water molecules through a semipermeable membrane. During this process, the contaminants are filtered out and flushed away, leaving clean, delicious drinking water. Reverse osmosis is capable of removing up to 99 percent of 65 different contaminants (see partial list below), including lead, fluoride, chlorine, dissolved salts, and more.
This pre-filter stage is designed to strain out sediment, silt, and dirt and is especially important as the sediment filter protects dirt from getting to the delicate RO membranes that can be damaged by sediment.
The carbon filter is designed to remove chlorine and other contaminants that affect the performance and life of the RO membrane as well as improve the taste and odor of your water.
The semipermeable RO membrane in your RO system is designed to allow water through, but filter out almost all additional contaminants.
In a four-stage RO System, a final post filter (carbon filter) will “polish” off the water to remove any remaining taste and odor in the water. This final filter ensures you’ll have outstanding drinking water.
There are many different Reverse Osmosis (RO) water filtration systems on the market. While one RO System may look like the next in terms of design and components, there can be substantial differences between systems.
In our 25+ years in the industry, we’ve found that the quality of components is truly the key differentiation between systems. This is because RO units manufactured using excellent craftsmanship, as well as superior parts and components are what ultimately produce the best intended results--top-quality water for the home and business.
As you compare RO systems to find the product that is right for you, be sure to ask yourself these 5 questions:
1. Replacement filters: RO membranes and filters will need to be replaced every 6 months to 2 years depending on the type of filter, your water quality and your water usage volume.
This guideline is very general. Specific information about how often your membrane or filter should be replaced can be found in the products’ “Specs” or your product owner’s manual. If you’ve purchased a system or filter from us in the past, we will send reminder emails when it comes time to change your filter.
2. Electricity Charges: All of our residential Reverse Osmosis systems require no electricity, running only on water pressure. Some of our larger commercial systems do have to use electric pumps, but even then the power requirements are minimal.
3. Annual Maintenance: We recommend that you have your RO system sanitized and filters changed once each year. This can be done by the homeowner or by a local water treatment professional. A water professional can provide needed maintenance service or consult your RO system’s owner’s manual. We also carry kits and the filters to perform the annual sanitation and filter change if you’re a do-it-yourself type.
If you properly care for your Reverse Osmosis system (annual cleanings plus change out filters/membranes on time), your system should have a very long lifespan; we’ve seen properly-maintained systems last 10-15 years!
We highly recommend that you purchase replacement filters from us as we only carry top-quality filters that are designed for optimal performance and reliability.Shop for Replacement Filters Shop RO Faucets Shop RO Membranes Shop Residential RO Systems
Generally, an RO system is installed and stored under the kitchen sink. Under-counter reverse osmosis systems have a holding tank and several phases of filtration. Here’s what happens during the reverse osmosis process of most systems:
Phase One: This is a pre-filtration phase designed to protect the unit’s membranes by reducing fine, suspended materials that can clog the system.
Phase Two: The second phase involves filtration to remove chlorine since chlorine can damage thin film-material membranes.
Phase Three: This is a semi-permeable membrane designed to remove a wide variety of both aesthetic and health-related contaminants. The water goes from here into a pressurized storage tank to hold the treated water.
Phase Four: The final stage in the RO process is usually a carbon post-filtration phase that will remove any remaining aesthetic taste or odors --a “polishing stage”, if you will.
Under-the-counter reverse osmosis systems are plumbed to the incoming cold water line, drain, and an independent faucet. But it is possible for a water treatment professional to plumb an RO unit to your fridge and/or ice machine, as well.
The water professional will most likely run a quarter-inch tube from the under-sink RO unit to your fridge. Water pressure is a consideration with some refrigerators, so be sure to refer to your RO system’s owner’s manual as the pressure from the reverse osmosis unit is about two-thirds of the incoming line pressure.
The typical under-counter reverse osmosis tank is 12 inches in diameter and 15 inches tall. The reverse osmosis system will operate under water pressure ranging from 40 to 100 psig and generate ten to 75 gallons (that’s 45-340 Liters) per day.
Generally, reverse osmosis systems are very quiet-- though you may hear a “gurgling” sound as the “concentrate” or waste water flows from the membrane to the drain. Reverse osmosis is designed so that “crossflow” water flushes the contaminated concentrate away from the system. This flushing keeps the unit from fouling.
If you hear other sounds, such as a “hissing” noise, immediately call your local water treatment professional as there may be a problem with water pressure, the air gap or a leak.
No. A residential reverse osmosis system simply runs on water pressure from household plumbing and requires no electricity. The exception to this is large commercial or industrial RO systems. These large systems use pumps to feed water through the filtration process.
Most people prefer reverse osmosis-filtered water over bottled water. An RO system that incorporates carbon filtration will remove chlorine, chloramines, arsenic, pesticides, herbicides and more. The removal of these contaminants not only makes for safer drinking water, but also greatly improves the taste. The RO process leaves trace amounts of minerals and salts which makes for an overall better taste rather than the “flat” taste of distilled bottle water. Best of all, RO-filtered water saves you the expense of bottled water and is better for the environment since you’re not adding water bottles to local landfill.
With proper maintenance, an RO system can last for many, many years. Filters should be changed at their scheduled replacement times. The carbon, sediment, and final polishing filters are generally changed out every 12 months and the RO membrane filter is replaced every two years. (These are general recommendations but water usage and household size are the determining factors). Occasionally, tubing or the holding tank will need to be replaced, but overall, RO systems are very simple and easy to maintain and will operate for many years.
Absolutely. Looking at cost alone, RO systems generally cost less than 30-cents per day to own and operate for a family of four. From a cost-savings perspective, since most Americans spend $100/year on bottled water translating to $400/year for the household, and an RO system would save nearly $300/year as it operates for roughly $100/year. And the number crunching doesn’t reveal anything about the health benefits of RO! RO systems can remove harmful contaminants such as pesticides, herbicides, chlorine, chloramine, and arsenic---certainly making an RO system “worth it.”
Tap water varies with each city and water source. Some tap water is heavy in mineral content which can affect the taste and smell of water. Filtering water with a reverse osmosis system will remove the majority of minerals in water and greatly improve the aesthetics of drinking water. Because minerals in water are in an inorganic state that our bodies cannot digest, removing the minerals does not make RO-filtered water unhealthy. So keep in mind that while minerals are essential for proper health, food is the primary source of the minerals our bodies need to be healthy, and in a form our bodies can digest.