Water quality is no joke, and frequent travelers may have little or no idea about what’s in the water at a campground. Having water filtration for your RV is considered a requirement by many RVers. Reverse osmosis systems are arguably the best water filters out there, but do they make sense for RVs? Join us as we take a closer look!
What Is a Reverse Osmosis System?
A reverse osmosis (or RO for short) system is a special type of water purification system. This type of water filtration system was originally designed to remove salt from the ocean for use on navy ships. Sometimes these systems are known as water makers on boats.
Reverse osmosis systems are known to produce some of the purest water you can get from a residential water system. They are the only types of systems that will remove dissolved solids from water including salts, metals, dyes, minerals, and more.
Most reverse osmosis systems are for point of use, meaning they are only for a drinking water faucet. This is because the system is very slow at producing clean water and frequently needs a storage tank.
How Does Reverse Osmosis Work?
To understand reverse osmosis, we first need to understand regular osmosis. You may remember this term from high school biology. This is because osmosis is the way fluids naturally move through semipermeable membranes. Fluid always naturally moves from areas of lower dissolved solids to higher.
Reverse osmosis is a pretty simple concept. The system takes pressurized water and forces it through a semipermeable membrane, which captures impurities. In reverse osmosis, water is pressurized and forced backwards through the natural process.
Frequently, reverse osmosis systems include multiple filters, each designed to eliminate various impurities. These include dissolved solids, chlorine, or other items that can affect water quality or taste.
The primary filter in an RO system is the RO membrane. This special membrane is ultra-fine and requires high pressure to force water through it.
Most water filters have a filtration size down to .5 microns, but a reverse osmosis system has a .0005 micron filtration. Because it is so fine it also requires that some water flows over it to constantly flush or “clean” it. This is called rejected or brine water.
This brine water includes many of the things that you are trying to remove from the water. The brine is usually discarded down the drain but sometimes is recycled for another trip through the RO filter.
After the water has been purified, it’s usually captured in a tank that can be used for drinking later. This tank is used because the RO process can be very slow, so to fill a glass up you use the tank water instead of waiting half an hour.
Can RO Filter All the Water for an RV?
Whole RV RO systems are possible thanks to the RV’s freshwater tank. As we mentioned above most RO systems use a tank to store up the clean water because the system is slow at generating water. While rarely done in a house due to the need to install large tanks and pumps an RV is primed to run an RO system.
A whole RV reverse osmosis system uses pressurized city water to force water through RO membranes. The RO system generates about 1 – 5 gallons every 30 minutes that flow to the RV’s freshwater tank.
The RV then uses its onboard water pump to pump this clean water as needed. When the tank is full a sensor sends a signal to a valve to shut off the RO water supply to prevent overfilling. Waste brine water runs into the grey tank and out to the sewer.
Whole RV vs. Drinking Water-Only Reverse Osmosis System for Your RV
Whole RV RO systems get a bit more complicated because you need to connect the RO system to a tank sensor that stops running the reverse osmosis when the tank is full. These systems are also limited to around 100 gallons per day, but this is usually more than enough water for an RVer.
While the whole RV reverse osmosis system might sound great, these systems are generally the most expensive and produce the most wastewater. A whole RO system is great if you are hooked up to city water but will not work well for filling the RV quickly. It can take an entire day for the tank to fill with RO water, and you need to do something with the brine.
Drinking water-only systems are usually installed directly underneath your RV sink and filter the water immediately before it leaves your faucet. These systems are cheaper and produce less waste, but don’t do anything to prevent impurities or other problematic items in your water from entering your appliances or plumbing fixtures.
Lastly, the easiest way to get RO drinking water is with a countertop system. These systems are reasonably affordable and deliver excellent-quality water. The AquaTru system is highly rated and very popular among RVers to get excellent quality water easily.
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How Much Do Reverse Osmosis Systems for RVs Cost?
If you are looking to cover drinking water only with an under-sink system some basic models can be less than $200. More advanced systems cost between $350 and $500.
For a whole RV system, $500 to 700 dollars is not uncommon as they require additional wiring into tank sensors and valves.
Pros and Cons of Reverse Osmosis Systems for RVs
While reverse osmosis systems for RVs have definite benefits, they’re not right for all RVers.
If you want the cleanest drinking water you can get, reverse osmosis is the way to go. If you frequently use unfamiliar water sources, this thorough purification can be essential for your peace of mind. You’ll also be able to make pure, clear ice from your drinking water.
In many places RVs go, the water also tastes terrible, but RO water is the only way to guarantee consistent good-tasting water.
Also, once you install your system, it’s cheap to operate on an ongoing basis. You’ll need to replace the filters occasionally, but otherwise, it’ll work without too much cost or maintenance. Most RO membranes will last between 1,500 and 3,000 gallons of water and will depend on the filter.
Cost is often the tallest hurdle for some RVers interested in a reverse osmosis system. Purchasing the necessary equipment and paying someone to install it can be a somewhat significant expense.
These systems are also wasteful. For every gallon of purified water, the system wastes several more as part of the filtering process. In situations where you only have a limited water supply, the wasted water can be detrimental.
It’s also important to note that RO water strips almost everything from the water, meaning minerals too. These minerals are important for proper balance in the body and when drinking RO water can actually be removed from your body by dilution. A solution to this is adding minerals back in with a product like ConcenTrace.
If using an RO drinking water system when not hooked up, it will significantly shorten your off-grid time. This is because it will waste so much water.
Some have tried routing the brine (wastewater) back to the freshwater tank. This can cause problems, however, because it concentrates minerals in the fresh tank, resulting in mineral buildup and deposits elsewhere in the freshwater system.
Is It Worth Getting a Reverse Osmosis System for Your RV?
If you spend a lot of time in your RV or frequently travel and use different water sources, a reverse osmosis system is a good choice to ensure water quality. It’s also an excellent choice for RVers who want the cleanest, purest water possible.
However, for infrequent travelers, those trying to conserve water, or RVers who stay hooked up to a clean, reliable water source, these systems may not be worth the cost to buy, install, and maintain.
Overall, reverse osmosis systems for RVs can be a valuable tool in staying healthy and keeping your rig safe while on the road. Though the waste, cost, and maintenance required means they’re not for everyone.
We personally do not use an RO system but rather a multi-stage filtration system with UV purification as the final step in drinking water.
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