Replacement Water Filters

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.What size filter housing do you have?

2.What specific water problem are you trying to treat?

3.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.

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

• Sediment Filters
  • Spun Polypropylene Sediment
  • Pleated Sediment
• Carbon filters
  • Granular Activated Carbon (GAC)
  • Carbon Blocks
• Bone char
• Calcite

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.