Your Blueprint for Choosing the Right Water Filter Housing & Cartridge

As a professional, you know that the success of any water treatment installation works on getting the fundamentals right. Your clients depend on you to deliver clean, safe, and reliable water, and that trust is built on the quality of the components you choose. But navigating the vast options for filter housing and cartridges can be a challenge.

This guide makes things simpler. We’ll let you know the essential choices, helping you specify the perfect system for any job, from a single-family home to a demanding commercial application. Let's ensure every installation is a success from the start.

The Core Components: Understanding the Filter Housing And Cartridge System

Every cartridge-based filtration system is a two-part team:

• The Filter Housing: This is the durable, permanent canister that is plumbed directly into the water line. Its purpose is to support the filter and the water flow. It's the central component of your system. It needs to be reliable and correctly sized for the job.
• The Filter Cartridge: This is the workhorse. It's the replaceable media that does the heavy lifting of removing contaminants. Selecting the right water filter cartridge is crucial for targeting specific water quality issues and achieving the desired outcome for your client.

Step 1: Selecting the Right Water Filter Housing

Choosing the correct housing isn't just about what fits. It's about matching the equipment to the application's flow rate and long-term service needs.

Size: Standard vs. Big Blue (BB)

• Standard Housings (2.5" Diameter): These are your go-to for Point-of-Use (POU) jobs, like under a kitchen sink or for a dedicated appliance. They're compact and effective for lower-flow applications.
• Big Blue Housings (4.5" Diameter): For any Point-of-Entry (POE) or whole-house system, Big Blue is the professional standard. The larger diameter allows for a much higher flow rate with minimal pressure drop. This is a critical factor for client satisfaction. It also means the filter has a longer service life, resulting in fewer callbacks for you.

High-Flow Commercial Solutions

For larger commercial or industrial jobs that demand maximum flow and minimal downtime, standard housings won't cut it. This is where solutions like Harmsco Hurricane filter housings come into play. Their innovative design provides exceptional performance and durability for the most demanding environments.

Inlet/Outlet Port Size

To avoid creating a system bottleneck, always match the housing's port size (typically 3/4" or 1") to the diameter of the supply line. For most whole-house installations, a 1" port is the best practice to maintain strong water pressure.

Step 2: Choosing the Perfect Water Filter Cartridge

With the housing selected, it’s time to choose the component that solves your client's water problem. A high-quality cartridge filter housing is only as good as the filter you put inside it.

Targeting the Problem (Filter Types)

• Sediment Filters: This is always your first line of defense. Made from spun polypropylene or pleated material, they remove physical particles like sand, dirt, and rust. According to the CDC, these particles are common issues, especially in well water, and removing them first protects every component downstream.
• Carbon Filters: These are for chemical reduction. They are masters at removing chlorine, unpleasant tastes and odors, and volatile organic compounds (VOCs).
  • Carbon Block filters are densely packed, offering very fine filtration and superior chlorine removal.
  • Granular Activated Carbon (GAC) filters contain loose carbon granules, which are excellent for chemical adsorption and result in a lower pressure drop.

Filtration Fineness (Micron Rating)

A "micron" is a millionth of a meter. A lower micron rating means a finer filter that captures smaller particles.

• 20-50 Micron: Good for capturing large, visible sediment.
• 1-5 Micron: The sweet spot for a general-purpose house water filter cartridge, removing fine silt and rust particles to deliver visibly clearer water.
• Sub-micron (<1 Micron): Essential for capturing extremely fine particles. You'll often find this rating on carbon block filters designed to remove cysts like Giardia and Cryptosporidium.

Put Your System Together With Water Treatment Supply

You're now ready to specify with confidence. The process is easy: you size the filter housing for the flow rate of the applicant, and then you select a cartridge that targets your specific water quality issue. 

At Water Treatment Supply, we have a full range of housings and cartridges that meet the demands of any project. You can find varied products below, and if you need further help configuring the right solution, know that we have experts waiting to help.

Frequently Asked Questions (FAQs)

1. How often should a water filter cartridge be changed?
   A general guideline is 3-6 months for sediment filters and 6-12 months for carbon filters. The best indicator, however, is performance. If you notice a significant drop in water pressure, know that the filter is clogged, and it's time for a replacement.
2. Can I use a different brand of filter in my housing?
   In most cases, yes. The industry uses standard sizes like 10" x 2.5" or 20" x 4.5" (Big Blue). As long as you match these physical dimensions, water filter housings are typically interchangeable. Always confirm the product specifications to be certain.
3. What's the real difference between a "Big Blue" housing and a standard one?
   The two key advantages are flow rate and service life. A Big Blue housing uses a much larger-diameter filter, which allows more water through with less resistance (pressure drop). Its larger surface area also means it can capture far more contaminants, lasting significantly longer than a standard filter. It is the superior choice for any whole-house application.
4. Should my sediment filter or carbon filter come first?
   Always install the sediment filter first. It removes the physical debris that would otherwise quickly clog your more expensive carbon filter. This simple step protects the carbon filter, allowing it to work efficiently on chemical contaminants and maximizing its lifespan.
5. My client’s water pressure dropped suddenly. What should I do?
   A sudden pressure drop is the classic sign of a clogged filter. The first step is to replace the first filter in the system, which is usually the sediment cartridge. If that doesn't solve the problem, move to the next filter in line. Proactive, scheduled filter changes are the best way to prevent these service calls.