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Whole House Water Filter

designed by ecologist James P McMahon

Jim McMahon ecologist

My Urban Defender is the Best Whole House Water Filter because it is Customized to Your Family and Your Water

"Some years ago, while selling another company's product, I realized I could design a whole house water filter that was more effective, cost you less, and cost less to maintain. So I did."

I put my knowledge about water quality and my experience in water treatment into the design. I believe that the Urban Defender™ is the best whole house water filter available today, equal to products that cost three times the price and far superior to many of my competitor's products that deprive you of effective treatment in order to appeal to you on price. I can't name names, unfortunatley, but I can tell you to avoid the cheap upflow carbon filters. You can email me and request an industry trade magazine article spelling out the reasons.

 Urban Defender whole house water filter

Sweetwater's Urban Defender™

the best whole house water filter

Extremely Effective - Great Value

Learn how it works! To learn what design features I use, keep reading or request the Urban Defender whole house water filter specifications to learn how it works.  This description includes the seven features to look for when choosing a whole house water filter system:

 Inquire Now:

 Send me your Urban Defender specifications and pricing

 The Urban Defender whole house water filter is custom built and I can modify each unit to match the chemicals in your water and the needs of your household. Hundreds of people now enjoy healthy showers using the Urban Defender whole house water filter. If I could make it even better, I would... Each year I take time out to research how I can improve the filter system and while I have made minor adjustments I am extremely pleased with the construction and effectiveness of the filter system components. I describe below why I think it is the best whole house water filter for your family.



Urban Defender™ whole house water filter with GAC: $2340.

Urban Defender™ with catalytic carbon: $2565.

Super Size (4 cu ft) Urban Defender™ for large homes/multiple showers: $4725.

An 8 cu ft Urban Defender™ for really large homes, bed and breakfasts, or commercial use: $6250.

5 micron pre-filter: $205. - always recommended

Optional add on filters:

Fluoride filter: see here - for whole house fluoride filters

Zeolyte (for trace levels of iron and manganese) filter: $325. (subject to change due to market conditions)

UV light: $1376. - whole house UV light, email me for specifications

You may also wish to use a water softener or the water revitalizer but whether or not I recommend these depends on what is in your water report as well as the priorities of individuals in your household.

To learn what you need start by finding your local water report and then calling me during business hours. We'll review it together and determine what suits your family. Don't fall for the cheap upflow filters that fail to remove all carcinogens.

The Urban Defender will remove the chlorine or chloramine and the carcinogenic chemicals, including the hard to remove trihalomethanes and haloacetic acids (look for those in your water report) in municipal water supplies. The trihalomethanes are absorbed by your skin and inhaled in the shower. They are among the most lethal contaminants we are exposed to daily. The Urban Defender will also remove the pesticides from farming.

"Among the THMs that result from chlorine combining with organic compounds in water are carcinogenic chloroform and carbon tetrachloride. It is the combination of chlorine and organic materials already in the water that produces cancer-causing byproducts. The more organic matter in the water, the greater is the accumulation of THMs"

The Negative Health Effects of Chlorine

Joseph G. Hattersley

I invite you to watch this short video in which I demonstrate quite clearly that chlorine is quickly absorbed into your skin when you shower or bathe:



The Urban Defender whole house water filter removes or reduces: volatile and semi-volatile organic compounds such as chloramine, chlorine, alachlor, atrazine, trihalomethanes, haloacetic acids, solvents such as benzene and MTBE, soluble metallic and non-metallic ions including but not limited to arsenic, cobalt, antimony, copper, mercury, cadmium, chromium, lead, chloroform, hydrogen sulfide, lindane, malethion and other pesticides, silver, and trichlorethane. If you have significant levels of any of these metals then I will recommend the addition of a reverse osmosis system at the kitchen sink because we want to be able to maintain high flow rates with the Urban Defender and that limits its effectiveness at removing metals.


"My Urban Defender has changed my life.  I love it!"

Aileen Gee; Falmouth, MA


The Urban Defender™ whole house water filter is available with catalytic carbon to remove chloramines or granular activated carbon (GAC) to remove chlorine or pesticides. Learn about choosing the correct size system.

All orders are by phone but you may request detailed specifications by email:

Send me your Urban Defender specifications and pricing

 Urban Defender Whole House Water Filter with Sweetwater's custom reverse osmosis system

Urban Defender whole house water filter with reverse osmosis mounted in a garage

If your water contains chloramines, a toxic combination of chlorine and ammonia now in use by many cities, then you need the catalytic carbon version. If your city uses chlorine then the GAC version will work just fine. If you have want to be able to use more than two showers at any one time then you need to use the Super Size version which has a higher flow rate.

The Urban Defender media is tailored to your water, the features, such as downflow filtration and the amount of carbon I use, make it effective at removing contaminants, and the quality of its components are the best in the industry. Mostly though I can honestly say that it is the best and most effective because I look at your water report as we talk and I build the system that will serve the needs of your family.


"San Francisco recently changed its water treatment and many of my neighbors were complaining about the color, taste, smell .... but we have the Urban Defender whole house filter and the Kitchen Defender (under the sink), and I truly never noticed a change. Our water is as tasty as ever."

Jessica M

San Francisco


The seven features that make the Urban Defender™ the best whole house water filter in America today:

First, the Urban Defender is a Downflow system, which means that the water flows down through KDF media and 2 cubic feet of carbon chips forcing the contaminants to come in contact with both media types, thus maximizing effective removal.

Second, periodic backwash reshuffles the carbon to present new carbon surfaces to incoming water, maintaining effectiveness throughout the five to seven year life of the initial media.

Third, you can choose between catalytic carbon for chloramine removal or granular activated carbon (GAC) for chlorine removal.

Fourth, the 2 cu ft Urban Defender is limited to a flow rate of 10 gallons per minute -  allowing for sufficient contact time between water and carbon to ensure removal of contaminants for the typical family home.

Fifth, for larger homes or homes with a greater number of contaminants a larger version is available. The important factor in this choice would be the number of showers or water features you wish to operate simultaneously. The size of the house itself doesn't actually matter. For smaller homes of one or two persons my Terminator model is ideal. The Terminator is intended to compete price-wise with the cheap carbon systems that don’t actually work well while out-performing them.

Sixth, the Urban Defender is reusable, meaning that when the carbon is saturated with contaminants you can easily replace the media in a little over an hour.

Seventh, I use media that has been certified by NSF (42 and 61) but I don’t make phony claims about how long the system will last or what it will do. What I do claim is an effective life of 500,000 gallons. This includes effective removal of the array of contaminants listed above. The companies that make claims of 3 million gallons are only talking about chlorine. The other carcinogens will be in your water after 500,000 gallons.

For a comparison to other water filtration systems, visit:

Whole House Filter Comparison

Finally, I can provide numerous pre or post treatment filter options to remove or reduce the other contaminants in your water - if necessary.  One thing that most people do not understand is that a whole house water filter, made by any manufacturer, does NOT remove all the contaminants in your water. It removes those contaminants that makes your water better suited for showering and bathing by removing contaminants that are absorbed by the skin or inhaled. You may need additional treatment with a kitchen water filter as well, depending entirely on what's in your water. 

The Urban Defender will out perform and out last competitors' systems. It is far superior to non-backwashing, upflow systems and equal in effectiveness to more expensive competitors backwashing systems while costing you less. 

Urban Defender whole house water filter Flow Diagram

As you can see from the diagram all of the incoming water is treated by a downflow design. The purpose of the backwash then is to reshuffle the media in order to provide new carbon surfaces to the water as well as to eliminate channeling.

I really encourage you not to be swayed by the lower price and false claims made about downflow systems that do not backwash or upflow systems. While tempting, these systems will not last long and you will end up having to replace them sooner. An honest estimate of their longevity is one fifth of the gallons they claim. Their lack of effectiveness is known throughout the industry and not just a statement made by me.

And you may request an explanation on why a downflow design with backwash is better than an upflow carbon filter: Backwash vs Upflow. They really are. Once again this entire issue comes down to the question of who you can trust to sell you an effective product. Look at my testimonials. With the products I sell you are getting the very best that money can buy.

The Urban Defender may also be combined with Ultra Violet light, a water softener, nitrate or iron removal, or an array of backwashing water filters to provide you with the best whole house water filter system - comprehensive and effective; all based on a review of your water report and the contaminants that must be removed to provide your family with healthy water.

Send me your Urban Defender specifications and pricing

I do not sell products over the internet and there is no shopping cart on this site.  To order, you call me and we will review your city's water report, discuss your goals, and determine which product will best meet your needs.  My phone number is in the top right hand corner of this page.

Urban Defender Product Reviews:

"Because I have chemical sensitivities, allergies, and other health challenges, I need the cleanest water. Jim and I discussed my particular requirements and sensitivities and arrived at a customized set of components for a whole house water filtration system, showering, and drinking. I intentionally waited a year after the installation to have the water analyzed by a national lab to see if the water filter system components were each still doing a good job, even at the point in time when replacement water filters were due. The tests came back with results that were near perfect: in all cases contaminants were below the national standard, and no contaminants and bacteria could be detected at all for the drinking water. This is the best whole house water filter because after many years and several systems the Urban Defender allows me to have peace of mind about my water. Thanks for your help and caring."

Diane, Asheville, NC


"It has been almost 2 years since we purchased and installed the "Urban Defender" and I can now without hesitation offer you my unqualified statement of satisfaction. The Urban Defender completely transformed the quality of our drinking water, which now is pure tasting goodness. To say we are thrilled is an understatement! Maintenance -- the simple annual replacement of the system's 5 micron filter -- is a snap and cost effective. I congratulate you on a fantastic product and will continue to tell friends and associates about the benefits of clean and pure drinking water.  You know your stuff.  Sincerely,"  

David J. Peebler Montclair, NJ  


Urban Defender whole house water filter with water softener

Urban Defender whole house water filter with water sofener

 See what my other customers have to say:

Sweetwater Product Reviews


 To see how my Urban Defender compares to other popular models, visit:

A Comparison of Whole House Water Filtration Systems


This comparison shows that the Urban Defender is equal in contaminant removal to whole house water filters that cost three to five times as much.  I am confident that your choice of the Urban Defender is the best choice for the health of your family.  If I could make it even better....I would.


Send me your Urban Defender specifications and pricing


Here is a video that shows my 8 cu ft Urban Defender for a home with 7 baths:

 Sweetwater's 8 cu ft Urban Defender 


This photo shows a 4 cu ft Urban Defender in Louisiana:

4 cu ft Urban Defender whole house water filter

 4 cu ft whole house water filter

The benefit of a larger size Urban Defender is that you can use more water in the home and still remove carcinogens

"What an amazing difference! We used to have a chlorine smell every time we opened the tap, now we have amazingly clean, odor free water. We purchased the Urban Defender with the additional fluoride filter, as well as Sweetwater's custom reverse osmosis system. The end result was that our water not only tastes fantastic but also feels great too!

Jim is awesome at what he does and he gives you personal attention through the entire process. He looked at our water reports. He helped design the perfect system. He helped us when the shipping went awry. He talked to the plumber when the installation took place. He overnighted us a part that was missing. Jim is a really great guy, and he really stands behind his product!
For anyone looking for a water filter, I can’t recommend enough Jim or his Sweetwater systems. You will definitely be thrilled with the end result."
Nicholas Saparoff
Franklin, MA

Sweetwater's Urban Defender® is the best whole house water filter because of its effective removal of contaminants and the facts about your water and home that go into the construction of each unit - custom built just for you. I have numerous systems in San Francisco, Oakland, Los Angeles, Denver, Chicago, Texas, Florida and other locations. Email or call to inquire


I always recommend that you use a 5 micron pre-filter. Here's a look at one after 6 months of Madison, WI water:


Are you drinking that?

When you call, you'll reach me directly.

Together, we will solve the water problems in your home.

Toll-free: 866-691-4214

Direct: 970-259-2171

Monday thru Friday 9 AM to 5 PM Mountain Time


"What's in YOUR Water?"

James P McMahon, ecologist
James P McMahon


Learn about my products and services here:

Home Water Purification Systems

To read more about this topic see this Wikipedia article

 To view my experience and credentials:

JPM Biography



I don't take American Express