Replacement Water Filters

Even the best water filter won't do you any good if you don't replace the filter cartridge regularly. At US Water Systems, we have a wide range of replacement water filter cartridges to fit all types of standard systems. Whether you need a carbon filter, a sediment filter, or filter to remove fluoride from your water, we've got a great selection, most of which are made right here in the USA. If you aren't sure what type of replacement water filters you need or if a specific filter cartridge will fit your system, call our friendly Certified Water Specialists at 1-800-608-8792, and we'll be happy to help!

When it comes to replacement water filters, there are a few pieces of information that you need to know before you can buy the right cartridge for your needs:

  1. Does your system use standard filters or a proprietary size?
  2. What size filter housing do you have?
  3. What specific water problem are you trying to treat?
  4. Do you need a filter with a specific micron rating?

As you can see, you need to know what type of filter you have and what you're trying to achieve before you can choose the best water filter replacement cartridge. Once you have this information, you can select between the different filters that will fit into your system.

Standard Vs. Proprietary

Before you replace your water filter cartridge, you need to know if your system uses a standard filter size or a proprietary size. Nearly all companies that make filter cartridges offer them in one or more standard sizes so that they'll fit in a wide range of filtering systems. Some manufacturers, however, make systems that can don't use any of the standard sizes – meaning that you can only buy water filter replacement cartridges from them. This lets the manufacturer charge you whatever they want for the replacement cartridges, since you don't have any other options.

At US Water Systems, we think that being forced to pay high prices for filters is unfair to you, the customer. That's why all of the water filters – and replacement water filter cartridges – that we sell use standard housing sizes. This way, you have the freedom to choose the replacement filter that you want, rather than being tied to just one brand.

Replacement Water Filter Cartridge Sizes

There are four main sizes for standard water filter housings:

  • 2.5“ x 10“
  • 2.5“ x 20“
  • 4.5“ x 10“
  • 4.5“ x 20“

A number of additional, larger water filter sizes are available, but these are more commonly used in large-scale commercial and industrial environments. In-line replacement water filters are also available, but they do not need to fit inside a filter housing, so sizing is less of a concern.

You can often easily determine which size filter you need by checking your water filter system's owner's manual. If you don't have the manual, it's simple to measure your existing filter to learn what size it is. Open your filter housing and remove the old filter. In most cases, you simple need to unscrew the filter cap and pull the old one out. Using a tape measure, measure across the top end of the filter to get the width and down the length of the filter to get the height. Now you know what size you need.

Mark Timmons, the Water Doctor, discusses how to correctly size a water filter.

Filter Cartridge Options

Once you know what size you need, you'll want to choose a water filter replacement cartridge that provides the water treatment that you need. There are many different types of cartridges available, and in most cases, you can change to a new filter type if you need it. For example, if you were using an activated carbon filter cartridge, you could replace it with a bone char filter in most cases.

Main Types of Filter Cartridges:

Each of these types of filters removes or treats a different type of water problem. Not sure which type of filter you need? Check out our water problems page or call a Certified Water Specialist at 1-800-608-8792.

Micron Ratings

If you want to physically remove contaminants from your water, you'll likely be looking for a filter with a specific micron rating. A micron is a size measurement, equal to one micrometer. A common example used to understand how small microns are is the size of a single human hair, which is about 90 microns wide.

Replacement water filters, like sediment filters, that are made to physically filter out contaminants are typically given a micron rating. These ratings can range from 50 microns down to 0.35 or smaller. While a lower rating means that the filter will remove more contaminants, it also means that the water will move through the system more slowly and the filter will typically need to be replaced more frequently.

the filtration spectrum