Culligan IC-EZ-4 Review: Universally Compatible Water Filter

Culligan IC-EZ-4 Review

What We Like

  • Fits multiple fridges and multiple cartridge filters
  • 4 filtration levels
  • Filter life LED indicator
  • Quick connect fittings
  • Easy twist-on, twist-off cartridge installation

What We Don’t Like

  • No alkaline remineralization for pH balancing

Bottom Line

If you are looking for a universally compatible water filter to fit in your refrigerator or for a countertop faucet, Culligan’s IC-EZ-4 is the ideal choice.


Even if the water supplied to your home is very clean, once in a while, some contaminants might get into the system. This usually occurs if there are leaks along the pipelines.

To prevent these contaminants from getting into your body, you should invest in a water filter. Culligan’s IC-EZ-4 is particularly unique because it has a universal design that can fit a wide range of cartridges and be used as an under-sink filter or in a fridge’s filtration system.  

Let’s dive into this review to learn more about this filter.

Culligan IC-EZ-4 Review

Culligan IC-EZ-4

Photo: Culligan

Filtration Effectiveness: 4 Levels

While this water filter is compatible with EZ-1, EZ-3 and EZ-4 filter cartridges, it comes with the EZ-4, which gives it 4 filtration levels.

These levels mean it reduces chlorine levels by up to 97% and particulates by up to 99%. At the same time, it reduces bad taste, odor, turbidity, and other contaminants such as VOCs, cyst, lead, mercury, and MTBE.

As a result, you get visibly clean and clear water that has a great taste and is ideal for cooking and drinking.

The filter is actually independently certified by NFS International to NSF/ANSI standard 42 and 43. This certification is done to ascertain if a filter reduces chlorine’s taste and odor, particulates, cyst, lead, MTBE, VOC, mercury, and turbidity.

This should assure you of the cartridge’s quality in delivering non-contaminated water into your glass.

That said, the filter has a flow rate of 0.5 GPM, which is quite enough for domestic use, and comes with a faucet that you can install on your countertop as a dedicated clean water source.

However, just like with other filter cartridges, a replacement is required every once in a while. This should be done every 6 months or after 500 gallons have passed through, depending on the water conditions and usage.

Well, how do you know when a replacement is due? The filter features a cartridge life indicator, which incorporates the use of an LED light to show if it’s time.

This LED flashes a yellow light to give you the warning that a replacement is due within 30 days. A red flash means it should be changed immediately. The battery required to run this system is included in the pack and you should replace it every time you replace the cartridge.  

Ease of Installation: DIY Installation

There is no need to waste your money by employing the services of a plumber to install this water filter. Since the unit can be used in a fridge, this installation is very easy and straightforward.

For under-sink installation, this requires some tools. According to the manufacturer, you need a drill, tape measure, Philips screwdriver, utility knife, adjustable wrench, pencil, Teflon tape, and safety glasses for keeping your eyes covered.

The installation process should begin by mounting the faucet and for this, you must have a hole drilled on your kitchen countertop.

Next, mount the filter system, in which you need to fix the filter head to the wall using its built-in bracket. After this, connect the supply adapter and filter inlet, then link up the faucet as the exit point. All fittings are included in the pack, including a 1/4-inch plastic tubing.

Lastly, fit in the cartridge then allow water to run through the system for about 10 minutes to flush air and carbon pieces out through the faucet. As the water runs through, check for leaks and follow the troubleshooting instructions if you spot any.

That said, detailed installation instructions are included in the user manual, and they include labeled part diagrams for easy guidance.

Maintenance and Replacement: Easy Cartridge Replacement

Maintaining this water filter is done by replacing the filter cartridge and as stated above, this should be done after 6 months or 500 gallons, depending on its use.

That said, replacing the cartridge is a very easy process because it has an EZ-change twist-on, twist-off mechanism. You can use any of the three Culligan cartridges (EZ-1, EZ-3, and EZ-4) as replacements but the EZ-4 is recommended because it is the most effective.

However, it is costlier and together with the EZ-3, lasts for only 6 months. On the other hand, the EZ-1 is cheaper and can go for up to a year, but is less effective. If your water does not have a lot of contaminants, this model can work well in your system.

The replacement process should begin by turning off the water supply and the detailed step-by-step instructions are also given in the user manual.

Price: Relatively Affordable

This under-sink filter is quite affordable, but it falls within the price range of this type of filter. Other than that, you need to factor in the cost of replacing the EZ-4 cartridge after wearing out, and this usually costs less than $50.

The EZ-3 and EZ-1 are much cheaper, with the latter costing less than $20.

Within Culligan’s lineup, there are two more under-sink water filters, which are the Culligan IC-EZ-3 and IC-EZ-1. These are not as effective as the unit under review because they contain less powerful filter cartridges.  

Additionally, these models are only compatible with the EZ-1 replacement cartridge while the IC-EZ-4 can fit all three.


A universally compatible water filter that can be fitted under the sink or in a refrigerator’s filtration system.

Because it can be fitted with either of the three Culligan replacement cartridges, this filter is universally compatible. This makes it ideal for cleaning water with different levels of contamination.

Additionally, you can fit the unit into any kind of refrigerator to give you clean cold water in the summer.


  • Product Name: Culligan IC-EZ-4
  • Product Brand: Culligan
  • Filter Life: 500 gallons (6 months)
  • Flow Rate: 0.5 GPM @ 60 PSI
  • Filtration: 4 levels
  • Micron Rating: 0.5
  • Product Dimensions: 4 x 5 x 15 inches
  • Weight: 3 lbs.
  • Warranty: 2-year limited

Key Features

  • Compatible with EZ-1, EZ-3, and EZ-4 filter cartridges.
  • Compatible with multiple refrigeration systems.
  • 4 level filtration system with NSF/ANSI certification.
  • Filter life LED indicator with battery.
  • Quick connect fittings.
  • Includes mounting bracket, installation hardware, and a chrome faucet.
  • EZ-change filter cartridge mechanism.