Whole House Water Filter vs Reverse Osmosis Systems

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Two of the most popular filtration systems are whole house filters and reverse osmosis filters. If you’re looking to buy a filter and you’re undecided between these two, we don’t blame you – they both have their benefits and impressive features.

In this guide, we’ve compared whole house water filters with reverse osmosis systems, helping you to decide on the best choice for your needs.

Whole House Water FilterReverse Osmosis
ApplicationPoint of entry (POE)Point of use (POU)
Micron Rating10-30 micron0.0001 micron
Water forWhole home needsCooking and drinking
Flow Rate6-25 GPM50-800 GPD
Upfront Cost$200- $10,000+$150 - $1,000
Maintenance Costs (yearly)$100-$400$90-$200

🚰 What Is a Whole House Water Filter?

A whole house water filter system is a series of filters housed within a single unit, installed at your home’s point of entry.

What does this mean? This type of filter is located as close as possible to the point where your main water line enters your home, upstream of your water heater. As a result, your entire home’s water supply – both hot and cold – can be filtered.

Whole House Water Filter Pros

The advantages of a whole house water filter are:

  • Provides filtered water to your entire home
  • Improves the quality of your drinking water, your shower water, and more
  • Different types of systems for different uses (e.g. city vs well water systems)
  • Thorough filtration
Springwell CF whole house filtration system

Whole House Water Filter Cons

The setbacks of a whole house water filter system are:

  • Fairly difficult to install; may need a professional plumber
  • Permanent installation; not suitable for rentals
  • Cost at least $1,000 for a reliable system

⚗️ What Is a Reverse Osmosis System?

A reverse osmosis system is also a series of filters within a single unit. However, for a system to be classed as a “reverse osmosis” system, it must contain a semi-permeable membrane. This membrane is made up of tiny pores that repel contaminants as small as bacteria.

Reverse osmosis systems can be installed as point of use or point of entry systems, but they’re most commonly installed underneath a kitchen sink due to their water waste.

Reverse Osmosis System Pros

Some of the benefits of a reverse osmosis system are:

  • Most thorough filtration – removes virtually everything
  • Several applications available, including under-sink, countertop, and whole home
  • Relatively easy to install
ro system on counter with dedicated faucet

Reverse Osmosis System Cons

Some of the setbacks of reverse osmosis filtration are:

  • Removes healthy minerals from water
  • Leaves water tasting quite flat
  • Wastes water

📝 The Key Difference Between Whole House Filters and Reverse Osmosis Filters

The main difference between whole house systems and reverse osmosis systems is their performance.

Whole house systems send water through a series of filter cartridges, or filter media, to greatly reduce contaminants. The contaminants become trapped in the cartridges and are unable to pass through with the water.

Reverse osmosis systems have an additional filtration stage – a semi-permeable membrane – that eliminates virtually all total dissolved solids from water, including minerals and metals.

Whole home water filter and reverse osmosis

🆚 Reverse Osmosis Water Filter Vs Whole House Water Filter Comparison

Let’s look at the different features of reverse osmosis systems and whole house systems for drinking water treatment.


The cost of a whole house water filtration system is anything from $500 to $2,000 or beyond. The cost of a system depends on the brand, the quality, and how specialized the performance is. For instance, air injection systems tend to be more expensive than cartridge systems because of their high-tech design.

Reverse osmosis systems vary in cost depending on their install location. Most under-sink reverse osmosis systems cost between $150 and $1,000, depending on the design and efficiency.

System TypeUpfront Cost
Traditional Reverse Osmosis$150 - $600
Tankless Reverse Osmosis$300 - $1,000
Countertop Reverse Osmosis$300 - $500
Whole Home RO System$4,000 - $10,000+
Cartridge Base POE Systems$150 - $4,000+
Tank based POE systems$1,000 - $4,000+


The design of a whole house system varies. Whole house water filtration systems for city water typically use carbon media alongside other media, like ion exchange, KDF, and activated alumina. A whole house carbon filtration system is available as a tank-based system or a cartridge-based system. Most whole-house systems are protected by a sediment pre-filter.

Reverse osmosis systems have a multi-stage design that combines sediment, carbon, and polishing filters, and a semi-permeable membrane. Traditional RO systems have a tank that stores filtered water, providing water on demand when you turn on your tap. Modern, space-saving reverse osmosis systems have a tankless design.

Frizzlife PD600 tankless RO system

Installation Location

As the name suggests, whole house water filtration systems are designed to treat your entire home’s water supply. So, these filters are installed as close as possible to water’s point of entry into your home.

Reverse osmosis filtration systems are more versatile. These systems can either be point of entry (e.g. filtering your whole home’s water supply) or point of use (e.g filtering only your kitchen sink drinking water). A whole home RO system wastes a lot of water, so point of use RO systems are the most commonly available.

Contaminant Removal

Whole house systems treat contaminants that are commonly found in drinking water, such as:

  • Chlorine
  • Chloramine
  • Heavy metals
  • Volatile organic compounds (VOCs)
  • Nitrate
  • Arsenic
  • Fluoride
  • Pharmaceuticals
  • Pesticides and herbicides

Not all systems are guaranteed to remove these contaminants, and some may remove more contaminants than those on this list.

Reverse osmosis filters deliver bottle-quality water straight from your faucet. This type of water filtration system removes more contaminants than any other filter. RO eliminates all the contaminants listed above, as well as:

  • Bacteria
  • Minerals
  • Salts
  • Cysts
  • Some types of viruses

RO produces completely pure water – but by removing minerals and salts, and can make tap water taste a little boring.

Removing dangerous impurities


Whole house systems have an efficient performance. Most systems don’t need to be powered by electricity and don’t waste water, so they’re affordable and low-fuss to run. Some whole house filter systems, like air injection systems, require backwashing, so these systems do waste some water.

The reverse osmosis process is becoming more efficient than it once was, but it’s still less efficient than any other water filtration method. RO water filtration flushes contaminants down a drain line, wasting water in the process. You can find less wasteful reverse osmosis systems with a wastewater to pure water ratio of 1:1, but traditional systems have a 4:1 ratio – meaning only 1 gallon of pure water is produced for every 4 gallons wasted.

System TypeWater Used (gallons)
Traditional RO4
Tankless RO0.33 - 1
Countertop RO0.25 - 1
Whole Home RO Systems0.2 - 2
Backwashing POE Systems30 - 50
Non-Backwashing POE Systems0

Maintenance Requirements

A whole house system dedicated to city water treatment needs, on average, once-yearly maintenance. Typically, the filters require changing every 12 months, although some cartridges may not last as long as this. A whole house filter system that uses pre-loaded media in a tank will only require maintenance every 5-10 years.

An RO filtration system has higher maintenance requirements than a whole house system. There are typically three separate filters to change in a reverse osmosis unit, with lifespans of 6-12 months. There’s also the semi-permeable membrane to replace, which has a lifespan of about two years.

Whole House Water Filters

Filter ReplacementsFrequency
Sediment Filter3 - 12 months
Carbon Filter6 - 9 months
Polishing Filter9 - 12 months
Tank Media3 - 10 years
Total Average Cost$100 - $400

RO Systems

Filter ReplacementsFrequency
Sediment Filter6 - 12 months
Carbon Filter6 - 9 months
RO Membrane2 years
Polishing Filter6 - 12 months
Total Average Cost$90 - $200

👨‍⚖️ Reverse Osmosis Vs Whole House Filtration: Which is Best?

Now that you know the key differences between RO and whole house filtration, you can decide on which method is best for you.

There’s no overall winner, here. It just depends on what you’re looking for.

For instance, if you want to drink bottled-quality water, but you’re not bothered about filtering the rest of the water in your home, an RO unit might make the most sense.

If you want to filter your drinking water and the water that you use for showering, washing dishes, doing your laundry, and so on, but you’re not bothered about achieving the highest-quality tap water, a whole house water filter might be the best choice.

When deciding between these two filters, consider your budget, your maintenance preferences, your water quality, and your intentions for a water filter.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

2 thoughts on “Whole House Water Filter vs Reverse Osmosis Systems”

  1. Avatar for Brian Campbell

    I live in Jacksonville, FL and have a water softener (WS) currently to reduce the water hardness for the city supplied water. Now wondering if I should be using a water filter for the entire house and/or just a Reverse Osmosis (RO) at the entry point for water in the kitchen for the sink & dish washer (or go total OCD and use a WATER FILTER (WF) for the while house + RO for the kitchen)?

    Will I need my WS if I go whole home RO? NO? If I go RO at the Kitchen entry point; then, YES for the whole home WS. And, would the WS go before or after the WF? There are so many options, the paralysis of analysis is beginning! HELP!!!


    1. Avatar for Brian Campbell

      Hey Lee,

      Thanks for posting your comment and questions. First things first, have you had your water tested? Do you know exactly what contaminants and water issues you are dealing with (including the hardness)?

      We always tend to recommend a point of use (POU) reverse osmosis system for drinking/ cooking water no matter what. RO provides broad protection against a range of contaminants, so it’s great for water that will be used for consumption.

      The main advantage of using a whole home (point of entry) water filter would be to have filtered water from every faucet, so you can reduce some contaminants from the water that will be used for hygiene purposes (showring, bathing, brushing teeth, etc.) as well.

      Whole home RO is a huge investment. It often requires additional pre-treatment upstream in order to protect the system. In your case, depending on the water hardness, you would most likely still need to soften the water upstream of a whole home RO in order to protect the system from scale formation.

      But again, it’s hard to say for sure without looking at the testing data. This is why testing before purchasing any water treatment equipment is so vitally important! You can use the data to guide your decision, which will help avoid analysis paralysis as well 😜

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