Reverse osmosis (RO) technology is considered the gold standard for water filtration across various industries due to its game-changing performance and reliability. However, as sophisticated and powerful as home RO filters are, they can be susceptible to premature, irreparable damage from large particles without adequate prefiltering of the water entering the membranes. If you have an RO filter installed at home or are considering investing in one, this article explains how prefiltration protects your filter membrane and helps keep your RO system running smoothly for longer.
Let’s start by looking at membrane filtration and how it works. We’ll then get into what makes a good pre filter for Ro before wrapping up with some specific recommendations on products that can help protect your RO membrane and extend its life span.
What is membrane filtration, and how does it work?
Membrane filtration is a water treatment process that cleans unfiltered water by forcing it through a porous or semipermeable membrane. This membrane works like a screen door that allows air molecules to pass through while blocking pests and anything larger than the holes in the screen door. In the same way, the filter membrane blocks ions, unwanted molecules, and larger particles in the water from passing through it (depending on the membrane’s pore size) and allows the water molecules to pass through.
Reverse osmosis and ultrafiltration are two of the most common methods used to purify water. While both of these processes remove a lot of dissolved inorganic compounds, they differ in how well they remove them. Reverse osmosis applies pressure to a semipermeable membrane, catching the dissolved inorganic compounds and allowing the water molecules to pass through. It separates the water into two pathways—the one with the molecules and the one with the dissolved compounds.
Ultrafiltration doesn’t separate the water like a reverse osmosis membrane. It is simply an ultra-fine particulate or sediment filter. With mechanical filtration, particulates down to 0.025 microns cannot pass through the ultrafiltration membrane.
Nano-filtration membrane technology works similarly to reverse osmosis, except the filtration is not as refined. This process cuts out particles smaller than 1 nanometer. These membranes are useful for applications where biocompatibility is an issue, because it removes toxic metals from a solution before it comes into contact with living cells and tissue
Why is Prefiltration Important to Your RO Filter Membrane?
When you use a Reverse Osmosis (RO) system to purify your water, you’re essentially relying on a membrane to trap unwanted particles while letting the clean water through. The membrane is only as effective as it is protected. If particles, dirt, and other contaminants aren’t removed prior to entering the RO system, they could potentially damage the membrane or cause costly downtime.
There are various ways to protect your membranes from harmful impurities. And many of them are really effective! But sometimes it’s hard to determine which methods will work best for your situation. For example, pre-filtering with granular activated carbon (GAC) is a popular method for removing organic compounds and odors from water. But GAC also traps some micron-sized particles that can damage your RO membranes, making this method a gamble in some cases. Fortunately, there are other options that ensure optimal performance without compromising protection.
How often should you replace your RO membrane filter?
Your home water supply has a lot of contaminants that can be harmful to your health. Your RO (reverse osmosis) system filters out different types of contaminants in order to provide you with the purest possible water for drinking, cooking, bathing and cleaning. The membrane filter that is used in an RO system does wear out over time and needs to be replaced periodically. It is recommended that you replace the membrane filter every two to three years, depending on your water purifier RO quality. If your RO system is still producing good-quality water after two or three years, you may be able to keep it for up to five years if you feed the RO system with softened water and replace the pre filters on time.
To get maximum life from your membrane, follow these maintenance tips:
1. Feed softened water into the RO system
2. Replace the pre filters on time
3. Replace the membrane filter at least once every two years