Birm Filter Media for Whole House Water Filters
In this article, we’ll take a look at how Birm works, along with some basic guidelines you need to know when using it. At the end, we’ll put everything together and build a sample system for an imaginary family.
Boilerplate Warning: Remember that filter media is only one component of an Iron Filter. Birm filters have their limitations. Our FREE WATER TEST is an easy way to make sure that Birm filter media is the right choice for your iron filter.
What is Birm?
Birm is actually an acronym that stands for “Burgess Iron Removal Method”. Birm filter mineral is produced by impregnating Manganous salts to a core made of Aluminum Silicate. This granular filter media is black in color and is moderately dense.
Birm Filter Media Specifications
|Service Flow Rate
|3.5 – 5gpm/sq. ft.
|Backwash Flow Rate
|10 – 12gpm/sq. ft.
|6.8 – 9.0
|Dissolved Oxygen Levels
How Does Birm Work?
Birm acts as an insoluble catalyst that enhances the reaction between Dissolved Oxygen (D.O.) and Iron/Manganese. Once oxidized, Birm filter media strains the contaminants out of the water.
Eventually the oxidized solids will begin coating the surface of the filter media and a powerful backwash or flush will be required to keep the media clean.
Like all Iron Filters, Birm must be backwashed according to the manufacturer’s specification. A weak backwash will either shorten the service life or stop the system all together.
Birm may be a strong enough oxidant on its own for iron levels up to 3ppm.
If Dissolved Oxygen levels are under 15%, the addition of an air injection system will be required to make the system work. Air injection along with a retention take large enough for 3 minutes of contact will greatly improve the performance of the system.
Birm must NOT be used on water that contains Hydrogen Sulfide or Tannins
Sample Birm Iron Filter Example
This example has a peak flow rate requirement of 8gpm (gallons per minute). If you have marginally poor water with 1ppm of Iron and no other contaminants, you could use a simple backwashing Birm Filter – WITHOUT PRE-TREATMENT.
A 12” diameter filter has 0.79 sq. ft. of surface area. Birm’s peak flow rate is 5gpm/sq. ft., so a 12” filter would provide 3.95gpm of filtered water (0.79 x 5).
So, for this example, we would use (2) 12” filters run in parallel.
Birm has a backwash and rinse rate of 10-12gpm/sq. ft., which is very similar to our Iron Curtain Filter Systems.
This means that each 12” diameter filter will require 8.7gpm to backwash and rinse. The complete system would use 261 gallons of water to regenerate EVERY THREE DAYS.
Birm is fairly easy to use when water chemistry allows the system to work without pre-treatment. Most water in the Twin Cities, however, just has too much Iron for a Filter-Only system to work.
From time to time, we use Birm Iron Filters when water chemistry is agreeable. With more severe water problems, we have found the flexibility of the Iron Curtain filter system to be much more reliable.
Who We Are
Premier Water is a local, family-owned water treatment company based in Chanhassen, MN. Since 1978, Premier Water has successfully implemented 1000’s of Residential and Commercial Filters and Purification Systems. We offer a FREE WATER TEST to gather information and help our clients with the right solution for their needs. We can also be reached at (952) 479-4553 for more information.