By Rehan Iqbal
Is a reverse osmosis filter right for your water treatment needs? How much does it cost to buy and install one of these filters? What alternatives should you consider? We're here to answer your questions, so you can make the right choice when you upgrade your water treatment equipment.
Prices vary widely depending on features, with under sink reverse osmosis systems typically ranging from $200 to $600. Tankless systems are the most expensive, because they need large RO filters to maximize water flow rate. Adding a larger storage tank or choosing a system with more filters also increases cost.
Be sure to budget a little extra if you want to hook up your under sink RO system to your fridge. If you already have a water line running to your refrigerator, you just need to add a T connector. This lets you send treated water to the faucet and the refrigerator. If this is a new installation, you’ll also need to add hose and clamps to run between the RO outlet and your fridge. Most manufacturers offer the hardware you’ll need as an add-on.
When you buy a system, it’s important to factor in the cost of replacement filters and their size. On average, an RO filter lasts two to three times longer than carbon and sediment filters. Larger filters last longer, but they may not fit in the space under your kitchen sink. Filters cost anywhere from $60 to $150 per year, depending on the number of steps in your RO system.
Can I Install an Under Sink RO System Myself?
If you can replace a faucet and drill holes, you can probably install an under sink RO system. You’ll need to drill a hole in your sink to mount the faucet, and another hole to connect the system’s waste water line to your sink’s drain line. From there, you just need to place the filters and run lines between everything.
How Much Does it Cost to Have a Plumber Install My Under Sink System?
Expect to spend between $100 and $200, depending on the complexity of your RO system.
How Much Does it Cost to Buy, Install and Use a Whole House Reverse Osmosis System?
Why are most RO systems only used for drinking water? Because whole house reverse osmosis systems are expensive, and come with their own problems. Here’s what you can expect if you choose this water treatment option.
The cheapest whole house RO systems sell for as little as $1,500, but units with enough capacity for a an average home cost between $6,000 and $20,000. Installation costs vary widely, depending on how close you can get the filter to your water main. If you can fit the system next to the water main, expect to pay a plumber between $200 and $500 for their part of the installation. If you can’t get the filter next to the water main, expect to spend at least an additional $5 per foot of pipe. If the plumber needs to dig or or cut holes in walls to run the lines, installation prices can easily exceed $1,000.
You may need to have an electrician wire up the pump. Like plumbing, prices vary depending on distance. If you don’t have ready access to a socket, expect to spend at least $200 for a new circuit and wiring.
Reverse osmosis removes all dissolved solids from water. Without these solids, water readily absorbs anything it comes across, including copper from pipes and lead from pipe solder. This can make your water toxic, and the water will eat away at your plumbing, leading to leaks. All metal pipes must be replaced by polyethylene (PEX) pipes before you can use a whole house RO system.
By using a whole house system, your water usage will be 2-5 times higher, as most of the water entering your home is turned into waste water. This might be too much water if you use a well. If you get water from a utility, this will have a big impact on your water bill.
Expect to spend between $200-$300 in electricity per year to drive the pump. Whole house systems typically come with just a carbon filter and a sediment filter. Be sure to factor in their replacement costs when you’re looking at RO systems.
What is a Reverse Osmosis Filter System, and Why is it More than Just an RO Filter?
There are four reasons why filter systems include more than just a reverse osmosis filter:
All RO systems include an activated carbon filter to remove chlorine. Most systems also include a catalytic carbon filter, a KDF filter, or both to remove even more chlorine. These filters also remove other contaminants, improving the flavor of water. Most systems also have a sediment filter, which prevents large particles from clogging other filters in the system.
Reverse osmosis removes so much that it leaves water tasting flat. Some systems compensate by adding a remineralization filter. This filter contains magnesium and calcium that dissolve into the water. This slightly increases water hardness, but not to a degree that it will cause staining around the faucet.
What Does a Reverse Osmosis System Treat, and What Alternative Treatment Methods are Available?
Since an RO system contains several filters, it removes more than an RO filter alone. However, these systems aren’t always the best option for treating your water.
Reverse osmosis is the best solution for removing these contaminates:
Reverse osmosis systems are an option for treating these contaminates:
RO filters don’t work well on these contaminates: