An RO membrane plays a key role in any modern water filtering unit, so ensuring that it is always in a good working condition is essential for the filtering process to go smoothly.
Knowing when to change the membrane or whether you should is also very important. Changing a membrane too isn’t cost-effective, changing it too late means you’ll have poorly filtered water.
Luckily, there are ways to determine if your reverse osmosis system is operating properly and they all rely on you educating yourself on how the system is intended to work and how to properly maintain it.
If you’ve already done that and your reverse osmosis system is fully operational, we could also assume that you know perfectly well when the time is right to change the RO membrane.
So let’s take a look at some of the best RO membranes the market has to offer so you can get a better idea of what’s out there.
Top 5 Best RO Membrane Options
1. Membrane Solutions Reverse Osmosis Membrane 50 GPD
A good RO membrane is supposed to have a high stabilized salt rejection rate and the Membrane Solutions Reverse Osmosis Membrane does just that. With an impressive 97% salt rejection rate, it reduces impurities by an impressive standard – including heavy metals, organic materials, and harmful minerals.
The membrane also features an industry-standard element size, unlike some of the other membranes in this price range, which makes it easy to fit in any standard 1812/2012 residential-style housing.
Its sturdy and durable construction guarantees a life expectancy between 24 to 36 months depending on average feedwater quality, which is quite a lot when compared to other membranes in its class.
Another quality you need to consider with RO membranes is material safety. This membrane benefits from a Thin Film Composite construction that not only allows for a high permeation flow but does so while safeguarding the RO system long-term.
Specifications:
- Filter size: 11.75”x1.75” (Fits Standard 2″ ID Membrane Housing
- Polyamide Thin-Film Composite material construction
- Micron rating of 0.0001μm
- A capacity of 50 Gallons per Day
- Feed pressure of 60 psi
Pros
- High salt rejection of 97%
- Long lifespan that stretches over 2-3 years
- Sturdy and durable construction
- Responsive on-demand assistance from the manufacturer
Cons
- Installation instructions could have been better
- The flow rate may be lower on certain RO systems
2. iSpring Greatwell Reverse Osmosis Membrane 75 GPD
Promising to eliminate up to 99% of all contaminants, the iSpring Greatwell RO membrane is a few steps ahead of many RO membranes in its class. Unlike others, this particular membrane will also filter out lead, chlorine, arsenic, calcium, and sodium, along with hormones and asbestos.
What’s interesting about it is that it was tested by independent third parties to meet NSF/ANSI standards, which is the standard you should expect from any decent RO membrane. The claim that it offers a near-perfect filtration appears to be backed by a large number of users.
Built from food-grade materials, it not only delivers an almost complete filtration but it will do so without posing any health risks whatsoever. Bear in mind, however, that this is a dry membrane and that its standards should not be expected from any of the wet membranes on the market.
It also needs to be said that this membrane enjoys a 0.0001-micron size that allows water molecules to pass through unrestricted but little of anything else. This ensures that your RO system will process up to 75 gallons of water on a daily basis with no limitations.
Specifications:
- Built to an 11.75” X 1.75” industry-standard size
- It is a dry membrane by design
- Has a capacity of up to 75 gallons per day
- Can last for up to 2-3 years
- Micron rating of 0.0001μm
Pros
- Filters almost any type of impurities with virtually no limitations
- One of the best dry membranes on the market
- Enjoys a high-capacity material construction
- Quality checked by independent reviewers
Cons
- Packaging is a bit difficult to open
- Once installed, it requires a lot of physical strength to remove
3. Watts Premier WP560014 RO Water Filter Membrane
A decent RO membrane can filter at least 20 gallons of water per day and that is precisely what you can expect from the Watts Premier WP560014 RO Water Filter Membrane. That said, its 24-gallon capacity isn’t anything to write home about. But what it lacks in capacity it certainly makes up for in filtering quality.
Speaking of which, this sturdy and effective membrane effectively reduces TDS and sodium along with several other contaminants like arsenic, lead, or chromium. It does so without stressing the RO system and without exhausting its filtering capabilities too quickly.
Interestingly enough, this membrane features a check valve that’s built straight into the body of the membrane itself. This valve allows for easy filter replacements by keeping you well-informed about the efficiency of its filtering efforts.
It should be noted that when installed in a decent RO system, it functions as a 50 GPD Membrane by most standards, with few limitations on its filtering capabilities. This change in water pressure is reliant on the construction of the RO system and how it’s set up.
Specifications:
- Measures 1.8 inches in diameter and it’s 10.75 inches long
- Perfect for 5-stage, 4-stage, and Zero Waste RO systems
- Build quality guarantees a 24-month life expectancy
- Comes in both 24-gallon and a 50-gallon versions
- Sturdy material construction makes it last long
Pros
- The kit comes with everything you need to install it smoothly and effortlessly
- Features a 5SV 5-stage RO module with five pre-installed filters
- Does not restrict water pressure in any considerable way
- Perfect for filtering tap water
Cons
- The packaging is a little flimsy
- It can make a dripping sound with some RO systems
4. Geekpure 75 GPD Reverse Osmosis RO Membrane Replacement
This NSF-certified membrane from Geekpure stands out as one of the most affordable membranes on the market. Despite its inexpensive nature, it performs just as well as other, more advanced membranes – if not better.
Part of the reason why this particular membrane is so effective is because it benefits from a polyamide film composite construction, which is both food-grade certified and completely BPA-free. This is something you normally expect from a high-end membrane so getting it from an inexpensive model is a definite plus.
We should point out that it’s designed with universal dimensions of 11.75″ x 1.75″, which should fit most RO membrane housings. The membrane surface is also built with multiple layers to guarantee a higher utilization ratio of water at any given time.
Although difficult to believe, some people have reached a 75 GPD flow with the membrane. However, they’ve had it installed on high-capacity RO systems. Other than that, the membrane seems to be working well with virtually any RO system provided that it’s compatible.
Specifications:
- Micron rating of 0.0001μm
- A Life span of 24 months or 35,000 gallons of pure water
- A potential of 75 gallons of water per day (with the right system)
- Multilayer construction
- NSF certified
Pros
- Made from food-grade materials, the membrane is entirely BPA-free
- Removes heavy metals, lead, mercury, fluoride, and many other contaminants
- Benefits from a friendly design that makes it easy to install
- Can fit almost any RO water filtration system
Cons
- It can eat a lot of DI resin with some systems
- It won’t last as much if the water pressure is too high
5. Aquatic Life GPD Membrane Filter for Aquarium
Despite the name, the Aquatic Life GPD Membrane Filter will work well with almost any RO system. This is thanks to its standardized construction, a build that also boosts its overall durability and versatility.
As you would expect from any decent membrane, this particular model removes TDS from tap water by freeing the water supply of any impurities, be they metal, mineral, or organic in nature. To be more exact, it can provide a near 98% filtering from any flow pipe or water storage tank.
A standout feature of this membrane is the universal compatibility that makes it perfect for any standard RO system. Its accommodating nature also ensures that virtually any RO system you install it on will match its high filtering capacity.
What’s more, the quality materials used in its making guarantee its long-lasting durability. In fact, the membrane will last you for up to 3 years under normal circumstances, provided that your water supply isn’t too polluted.
Specifications:
- Features an 11-3/4″ standard construction
- Rated for 65 PSI
- Up to 98% TDS reduction
- Water supply above 77°F produces more purified water
- Reduced dissolved solids down to 1/10,000 of a micron
Pros
- The membrane can last for up to 3 years before it needs replacing
- Its standardized construction makes it very accommodating to RO systems
- It works very well with high water pressure
- The sturdy construction makes it very reliable
Cons
- The membrane seal is attached very close to the OEM seal
- A bit pricey
What to Look For in an RO Membrane
Seeing how most reverse osmosis systems work by using high pressure to force water through semi-permeable membrane filters, you can expect the membrane to deteriorate over time. On average, this takes between 2 to 3 years depending on the membrane’s build, feed water quality, frequency of use, and material construction.
Operating Pressure
One thing to consider is the membrane’s operating pressure. You need to remember that decent membranes will work with water pressure between 40 and 100 PSI, sometimes higher. A water supply of below 65 PSI produces less filtered water whereas pressure above the 65 PSI margin generates more clean water on average.
Total Dissolved Solids Reduction
Referred to as (TDS), this determines how many impurities the membrane filters in order to increase clean water flow throughout the system. In this respect, the highest TDS you can expect is around 1/10,000 of a micron.
Filtering Efficiency
For you to get clean water, the sediment filter has to clear the processed water of as many impurities as possible. Decent RO membranes will deliver an almost 98% reduction in impurities, whether they are organic, mineral, or chemical in nature.
Size
When it comes to size, you should remember that RO membranes, as well as replacement filters, are always built according to specific industry standards. Although there is a certain degree of variation for replacement filters, when it comes to RO membranes the standards are a bit more rigid. The most common standards here are the 1812-50 and the 2012-100, which will work with most RO filtering systems on the market.
When Should I Change My RO Membrane?
A good way to determine if your membrane is no longer operating at optimal efficiency is to check how many liters of water it processes on a daily basis. At the same time, if your RO system is running constantly throughout the day, it may also be a sign that the RO membrane is no longer reaching its full potential.
Just like water filters, RO membranes should be replaced every 2-4 years depending on your RO system. That said, you can keep it for longer than that if the quality of the filtered water is still good enough to drink.
You determine if your membrane is doing its job well by measuring the TDS (Total Dissolved Solids). This represents the amount of salts, minerals, or metals dissolved in any given volume of water.
Keep in mind that the water quality in most urban centers is about 300 to 550 ppm while well water can range between 30 to 20,000 ppm. Depending on your personal preferences, you can set your RO filtering system accordingly.
Final Verdict
Although each RO membrane has its built-in particularities, a brief look at them would tell us that:
- The Membrane Solutions Reverse Osmosis Membrane benefits from a safe eco-friendly material construction.
- No other membrane filters contaminants as well as the iSpring Greatwell Reverse Osmosis Membrane.
- Watts Premier WP560014 RO Water Filter Membrane is perfect for unusual contaminants like arsenic and rare metals.
- If you’re looking for a fast replacement at a cheap price, you can’t go wrong with Geekpure 75 GPD Reverse Osmosis RO Membrane.
- The Watts Premier WP560014 RO Water Filter Membrane will work with virtually any type of RO system.