(8 Tips) How to Choose a Whole House Water Filtration System

Whole house water filters are a life-changing investment – but only when you invest wisely.

These complex water filter systems can set you back hundreds, or even thousands, of dollars. With such a lot of money involved, it’s important to make an informed purchase to avoid making a costly mistake.

In this guide, we’ve covered the step-by-step process of choosing a whole house water filtration system. As long as you follow the points in this guide, you’ll spend your money on a whole house water filter that ticks all of your boxes.

📋 Choosing a Whole House Water Filter: Step by Step

Follow these steps to make sure your whole house water filter:

  • Is the right size
  • Removes the right contaminants
  • Suits your budget
  • Is reliable and trusted by customers
  • Has third-party proof of performance

Step 1: Test your Water

You can’t buy a whole house water filter system until you know what you want to remove.

Test your water, either with an at-home water testing kit or private laboratory testing, to find out what it contains.

Common contaminants to test for in city water are chlorine, lead, pesticides, herbicides, volatile organic compounds, and hardness minerals.

👉 Test your city water here with Tap Score.

Common drinking water contaminants to test for in well water are iron, manganese, hydrogen sulfide, tannins, sediment (like rust particles), biological contaminants or organic contaminants (like bacteria), and hardness minerals.

👉 Test your well water here with Tap Score.

Once you have a roundup of 5-10 contaminants that are most prominent in your water, you can begin the process of looking for a filtration system that can remove them.

tap score water test report

Step 2: Set your Budget

It’s easy to get overexcited with all the whole home water filters available today, and buy the one that sounds the best – even if it’s massively out of budget.

A whole home filtration system needs to be affordable up-front, of course. You also need to be able to afford essential system maintenance, such as filter replacements.

Before you even start the research process, set your budget. Most whole home filters cost between $250 and $1,000, depending on their complexity.

The cheapest filters tend to need the most maintenance, so you’ll pay more for them in the long run. This could work best for you if you’d rather pay a small ongoing cost instead of a large upfront cost.

Step 3: Choose your Type of Water Filter

There are tens of different whole house water filter systems available today. Each of these systems is designed to remove a select group of contaminants.

Consult your list of contaminants. Use this to shortlist the available water filtration systems to those that can remove your contaminants. You’ll probably be left with 2-4 system types.

Common types of water filters for whole home use are carbon filters (remove heavy metals and chemicals like chlorine), sediment filter cartridges (remove sediment particles larger than 1 micron), ion exchange systems (target minerals), reverse osmosis filters (remove dissolved solids), and air injection filters (remove iron).

If you need more information about the types of whole house water filters available, we’ve covered all the most common filtration systems in this guide.

You can also get more info on POE systems vs RO systems in this guide.

Different kinds of water treatment

Step 4: Size the System

Whole house water filtration systems are fairly large, but they don’t all take up space in the same way.

For instance, cartridge-based filters are likely to be wider than they are long to account for all the filter cartridges in the unit. Media-based filters are usually longer than they are wide, consisting of a single tank containing media.

Measure your planned installation location and compare these measurements to the size of the whole home water filtration system you’re interested in. Repeat this comparison if you’re considering multiple filters.

There needs to be enough space in your install location to comfortably locate the filter system and perform maintenance, such as filter changes.

Step 5: Check the System’s Flow Rate

It’s essential to know the flow rate of a whole house filter system, and how this could affect the pressure in your water supply.

Water flow rate is measured in gallons per minute (or GPM). While most whole house filtered water systems shouldn’t affect your flow rate, under-sizing the system for your home can cause water flow to drop.

The system should have the right flow rate for your home’s size, water usage (at peak use), and number of bathrooms, to prevent low water pressure. Find out more about whole house filter flow rate here.

Flow rate

Step 6: Consider Installation and Maintenance

Whole house water filters can usually be DIY-installed, but not all filters are as easy to install as they’re made out to be.

Before you buy a whole house water filter, if you plan to install the system yourself, read the user manual and watch the manufacturer’s installation videos (if there are any). Read customer reviews to determine how easy customers like yourself found the installation process.

Keep in mind that your system might not come with everything that’s needed for installation. For instance, it’s handy to install a bypass valve that lets you switch between filtered and unfiltered water during filter maintenance. Not all units come with a bypass valve, so you may need to buy one as an extra.

Maintenance is another big consideration to make when looking at whole home water filters.

Cartridge-based filter types typically require the most maintenance because filter cartridges need replacing every 6-12 months on average.

Tank-based systems, like carbon media filters, air injection filters, or water softener systems, typically need less maintenance. Media and resin tend to have a lifespan of 5-10 years or longer.

Professional versus diy installation of whole house water filter

Step 7: Ask Yourself if Whole House Filtration is Right for You

By this point, you should have almost completely narrowed down your choices, and you’ll nearly be ready to part with your money.

It’s worth asking a question before you buy the filter: “is a whole house filter what I need?”

Some types of water treatment systems, like water softeners and air injection filters, are only available as whole home units. So in this case, you have no choice.

But many other types of filters, such as carbon filter systems, can be installed further along your plumbing system. If you just want to filter water for drinking, consider a point of use system, like faucet-mounted filters, under-counter reverse osmosis systems, or distillation systems.

But if you want to filter your entire water supply, providing clean drinking water, improving your shower water quality, and protecting your washing machines and water heaters, it’s worth spending more money on a system for your entire home.

Step 8: Look for Testing or Certifications

The final step is to compare your shortlisted filtration systems for third-party testing and certifications.

Third-party testing offers reliable proof that a filter does exactly as advertised. If a filtration system has an official NSF certification, even better. NSF testing is especially rigorous, and an official NSF certification proves that a filter is capable of effectively treating highly contaminated water.

nsf logo

Most manufacturers are keen to show off an NSF certification as a mark of quality, so you should find this information easily in the product description.

Following the steps in this guide, you should find the best solution for your water quality issues.