Reverse Osmosis Drinking Water Systems - What are they and why we all need one.

Reverse Osmosis filtration is a process where water is forced through a semi-permeable membrane to reduce total dissolved solids and other contaminants from water to supply clean, fresh drinking water.  A typical residential reverse osmosis system will have 3 to 7 stages of filtration consisting of a 5-micron sediment pre-filter, an Activated carbon filter, a Block carbon filter, a Reverse Osmosis Membrane, an In-line Activated carbon post filter, and a water holding tank.  The pre-filter and carbon filters are there to remove sediment and any chlorine that may be present in the water supply to protect the membrane from becoming fouled out with iron and large particulate matter to protect the reverse osmosis membrane.  The RO membrane is the essential stage of filtration and removes up to 99% of contaminants that may be in the water supply.  The list of contaminants a Reverse Osmosis drinking water system will remove is extensive.  There are many potentially harmful contaminants in drinking water such as Nitrates, Lead, Arsenic, Trihalomethanes, "VOCs" (Volatile Organic Compounds), PFAS, and many more that are potentially harmful to our health. A Reverse Osmosis Drinking Water System is designed to reduce or remove these things to give us high-quality drinking water. 

Let's look at the Reverse Osmosis Process and how drinking high-quality, pure water, every day can help our health and save us money. 

The Reverse Osmosis Process:

The RO membrane consists of many layers of spiral wound filaments which restrict the passage of contaminants and force them to the drain.  The product water is drawn from the inside of the membrane and sent to a storage tank before it goes through final carbon filtration as it goes to the RO faucet or refrigerator.  A typical residential Reverse Osmosis system makes anywhere from 10-75 gallons per day of high-quality drinking water depending on the TDS (Total dissolved solids) of the incoming water supply, feed pressure, and temperature of the water. Generally the higher the TDS less product water and lower quality water will be created. For high TDS water a “Booster Pump” is used to boost the incoming water pressure to the membrane to improve the quality and quantity of water produced.

Cutaway of a Reverse Osmosis Membrane and RO Membrane in filter housing:

Particulate size removal chart for a Reverse Osmosis system:

Diagram of a Reverse Osmosis System installation under a sink:

When feasible it is recommended to have the reverse osmosis system installed in the basement for easy maintenance, and filter changes and to not tie up valuable space under the sink.  Larger storage tanks can be used when installed in the basement and product tanks can even be hung in the floor joists to help with water pressure to the RO faucet and refrigerator.  Delivery pumps can also be used to boost the pressure from the storage tank to run water across the basement, operate refrigerators efficiently, and supply higher pressure to multiple locations and RO faucets.  RO filters are changed every 6-12 months and the RO membrane is changed every 3-7 years depending on water usage and incoming water quality to the RO.  Filter changes can cost anywhere from $60 to over two hundred dollars depending on the RO system and the type of filters to change.  RO membranes generally cost $65 to $120.  Anyone can change these filters but certain procedures need to be followed when changing RO filters to protect against bacterial cross contamination from our hands that can potentially contaminate the RO system.  Periodic sanitizing of the complete RO system is recommended to prevent possible contamination.

There are three styles of residential reverse osmosis systems:

   1.  Basic RO system with 3-7 stages of filtration

            2.  3-4 stage RO system with a one-piece manifold and replaceable filters

  
   3.  3-6 stage RO system with a one-piece manifold and quick change filter cartridges

Reverse Osmosis storage tanks come in many sizes to accommodate necessary water storage:

Rather than getting into the histrionics about dangerous things that can potentially be in our water and how they can be hazardous to our health, let’s just address one fact.  We all need to drink more water!  Our Doctors tell us that, our bodies tell us that every time we get thirsty, we all need to get away from drinking so many sugary drinks, energy drinks, coffee, drinks with artificial sweeteners, etc, etc.  Dehydration is actually the number one contributor to health-related issues.  Our bodies are over 80% water so keeping hydrated is of the utmost importance and drinking water is the only way to rehydrate.

Having to constantly buy water is time-consuming, expensive, and a pain to constantly be buying bottles of water or scheduling water delivery.  Not to mention finding the space to store it all.  All of us need to drink more water and many of us are, evidenced by the bottled water that is flying off store shelves and being delivered to households every week.  The bottled water industry has been growing by nearly 15% annually.  A Reverse Osmosis drinking water system is the answer to this problem and the most practical way of having all the quality drinking water we need (AT PENNIES PER GALLON) and will give your family high-quality drinking water 24/7, 365 days a year.  So do yourself a favor!  Get a Reverse Osmosis system for your family and DRINK UP there is plenty of water for everyone!

Here are helpful links about reverse osmosis, drinking water contaminants, drinking water regulations, and concerns about what may be in our water.

Wikipedia - What is Reverse Osmosis

http://en.wikipedia.org/wiki/Reverse_osmosis

EPA - Drinking water contaminants

http://water.epa.gov/drink/contaminants/index.cfm

EPA - Groundwater and Drinking water

http://water.epa.gov/drink/

Wikipedia - Contaminant levels

http://en.wikipedia.org/wiki/Maximum_Contaminant_Level

How Stuff Works - Reverse Osmosis

http://science.howstuffworks.com/reverse-osmosis.htm

Water Sense - Reverse Osmosis

https://www.epa.gov/watersense/point-use-reverse-osmosis-systems#:~:text=RO%20is%20the%20process%20by,VOCs)%2C%20PFAS%2C%20arsenic%2C

I wish you, Good Days, and Good Water!

Ray McConnell

The Water Softener Blog

© All rights reserved. Copyright "The Water Softener Blog"

"Water Filters" part 2 - When, What, Why and How to use a whole house filtration system.

Hellenbrand's next-generation Iron Curtain

In this second installment of "Water Filters," we will be looking at whole-house filtration systems for iron, manganese, and hydrogen sulfide removal along with iron bacteria and coliform bacteria. When to use a whole house filtration system, what to use, why use a particular type of filter system, and how to apply the right system for your water and family.

Frequently, water treatment professionals refer to water that is extremely high in iron, manganese, and H2S as "problem water" because it can be a challenge at times to find the proper solution to treat particular water problems and, quite frankly, it can take some experimenting with different methods to finally find the right water treatment method that works effectively and consistently.

In the first article "Water Filters Part 1" we discussed using cartridge-style pre-filters. As discussed, they are mainly for sediment removal although there is a myriad of cartridge filters that can be used for chlorine and lead removal, along with taste and odor filters.  The types of cartridge filters available (for specific water problems) and sizes are just mind-boggling. As discussed in this blog, a proper water analysis is the most important first step in determining the right water treatment solutions for your water.  In doing research for this blog I looked at quite a few "YouTube" videos because I was curious what some of the so-called "water experts" were

This is a nightmare!!

recommending for iron and odor filtration. What I would say from the videos I watched is "Don't watch any of those videos!"  They all pretty much recommended exactly what I said not to do in Water Filters 1.  Listen, if you have too much iron or ANY odor in your water putting a filter cartridge before or after the water softener is a very short-term fix and is NOT going to solve the problem, period!  Even if you put a bigger filter or a series of bigger filters before or after the water softener it won't fix the problem!  All you will end up doing is spending a lot of money replacing filters and having water that is "OK" until the filters get plugged up again. And guess what? That 20" BB carbon filter you need for odor removal, could easily cost over $100.00 every time you change it, for a short-term fix, possibly every 1-3 months or more frequently!  That is just not a practical solution to the problem or a cheap solution in the long run.

Bad, rusty, smelly, hard water problems take the proper water treatment approach to assure consistently great water for many years, and finding the right water treatment professional to fix your water problems can be like winning the lottery. It's been my experience that for every water treatment expert, there are ten, (what I like to refer to them as), hit-and-run water treatment companies. They literally just take your money and run and don't solve your water problems. It pays to do your research and find a good water treatment expert to keep you in great water and support you for years to come. If you want to do this yourself, and you are handy at plumbing then you've come to the right place!  We help you understand how this all works and find the right water treatment solutions for your water and family.

What is the easiest way to tell if you need a whole-house water filtration system?
1.  You need to use water softener salt like Red Out salt, System Saver salt, Iron Fighter, etc. to help your water softener remove iron or manganese.
2.  You use any powered additives like Iron Out, Rust Out, Softener Mate, etc., to treat your water softener for iron/rust problems.
3.  You are constantly cleaning the toilets, showers, dishwashers, and sinks regularly to remove rust stains or black stains.
4.  The women in the home need regular hair treatments to remove iron from their hair. Then again orange/red hair is in vogue these days!
5.  Your clothes come out of the wash with rust stains, discoloration, or spots. Especially whites.
6.  Your water is consistently discolored. Especially the hot water and bath water.
7.  Your water is constantly rusty, smelly, has a musty odor, or has a swampy smell to it.
8.  Your water is causing corrosion on sinks and appliances. Rusting out or even eating metal away.

If you answered yes to any of these questions you need a whole house water filtration system.  In our area, about 80% of the well water we treat needs an iron/odor filtration system, before a water softener, to assure all the iron and manganese are removed along with the trace amount of hydrogen sulfide.

I can't stress enough that a proper water analysis is key in finding the right water treatment solution to treat your water.  Especially when it comes to problem water solutions.  PH levels play an especially important role in these problem water solutions as acidic water makes it much more difficult to oxidize, precipitate, and remove iron, manganese, and H2S.  If the water is too acidic (below 6.5 PH) an acid neutralizer, such as calcite and corosex media, may need to be added to elevate the PH to levels above 7 (Neutral). There is a myriad of filter media options to choose from to treat every water problem so I will just stick with the most prevalent filtration media for problem water treatment. Every water treatment dealer has their preference and knows what works best in their area by trial and error. In reality, it's really practice, practice, practice by water treatment dealers to determine the proper water treatment solution.

Another very important aspect to look at when treating any well water is the well itself.
1. Is the well cap intact and sealed properly?
2. Is the well tank working properly? Is the pressure switch working properly, does the pressure gauge work, is the well tank holding pressure, is the well tank waterlogged, and does the well tank have the proper precharge pressure for the switch.
3. Is there enough water pressure and gallons per minute of water to operate a water treatment system efficiently. The minimum water pressure should be 30 psi. The minimum "gallons per minute" flow rate from the well or cistern should be 10gpm.

The most important thing in beginning to solve your water problem is to take notes on what you see going on with the water inside the home and outside. If you hire a water treatment professional discuss this with them fully. Take them around the house, and show them the problem areas. Toilets, showers, dishwashers, etc. When helping a homeowner solve their water problems listening to them as they describe the problems with their water is always the first step and is vital in any treatment solution. Homeowners live with their water every day and may have valuable insight into something that is not quite apparent at the time the water is tested.  Water can be really weird at times and the people living with it every day have a lot of insight into helping solve their water problems and providing them great water!

Whole House Filtration System Options.

  Manganese Greensand Filter

1.  Manganese Greensand filters - These systems use either potassium permanganate (Oxidizing chemical) or chlorine to oxidize and regenerate the filter media. Typically regenerates every other day or by gallons used. MTM media is also an option. It is lighter, easier to backwash, and has higher service flow rates.

Pros: Reasonably priced, fairly inexpensive to operate, does a good job at removing lower levels of iron, manganese, and H2S.

Cons: Requires a lot of maintenance and regular service. The media is very dense and heavy. Consequently, it has very low service flow rates (3-7 GPM) necessary for today's modern households and requires higher water pressures (30+ lbs) and water volumes to effectively backwash and regenerate the media.


2.  Chlorine or Hydrogen Peroxide Injection - Injection/retention/oxidation and filtration to oxidize iron, manganese, hydrogen sulfide, and filtration tank to remove oxidized particulates and residual chlorine or peroxide. This type of system is also frequently used when bacteria is a continual problem from the water source.  With difficult bacteria problems often this is the only option for treatment. Contact time (center blue tank) is vital in this application for the chlorine/hydrogen peroxide to have time to oxidize or sanitize whatever the water is being treated for. Filtration to remove oxidized matter comes next then carbon filtration to remove residual chlorine or peroxide before household use. With extremely high levels of Hydrogen Sulfide, Bacteria, and Iron Bacteria, this is often the only option to treat the water.

Pros: A very effective method of oxidizing iron, and manganese, removing hydrogen sulfide, and sanitizing the water. When iron bacteria or coliform bacteria are a continuous problem in well water supplies this is one of the best methods to ensure bacteria-free water.

Cons:  As you can see from the diagram this can be a rather complex system and can require weekly maintenance having to add chlorine or peroxide along with regular maintenance on the entire system to assure proper operation. Chlorine by-products such as Trihalomethanes are known to be carcinogenic.

3. Ozonation - Ozone treatment is also an option for oxidizing iron, manganese, and hydrogen sulfide, and treating iron bacteria and nuisance bacteria from your well.

Pros: Ozone adds nothing to the water, other than pure oxygen, and is an effective oxidizer for iron, manganese, and hydrogen sulfide removal. It's also very effective at killing bacteria such as coliform, iron bacteria, and sulfate-reducing bacteria. It's also very effective at removing Microbes, Giardia,
Cryptosporidium, Fungi, molds, parasites, and common odors in water.

Hellenbrand Residential Ozone System

Cons: Ozone has a very short lifespan, seconds. So it must be constantly generated. Ozone systems can be very maintenance intensive and require an experienced professional to maintain and apply properly. Ozone can be very corrosive to copper and galvanized plumbing as well. The indoor environment the ozone is created has to be very dry so most residential basements are not good environments for this. Frequently a separate air dryer is necessary to properly dry the air out in basement applications so the ozone generator works properly.


4. Aeration - Aeration is a filtration method that uses air either drawn into or injected into a filter tank to oxidize iron, manganese, and hydrogen sulfide.  The types of filter media used for aeration systems are endless. Birm, Filter AG, Multi-media, Zeolite, and Centaur carbon are just some of the different types of media used in this type of filtration system.

Early Aeration systems used an inline "Venturi" nozzle which drew air into the incoming well line, when the submersible well pump was running, before the well tank. As shown in this diagram. The iron and manganese are oxidized in the bladder style well tank, and frequently an additional aeration tank, then filtered out with a backwashing filter.  The problems with this venturi-style system are several.
1. The venturi nozzle creates so much back pressure on submersible pumps they run continuously trying to build pressure at the well tank. Eventually, the submersible pump will overheat and fail.
2. The venturi nozzle greatly restricts the water pressure and water volume causing insufficient water volume to properly backwash the filter media tanks. Causing the filter media to foul out prematurely. Hence these systems typically need the filtration media replaced every 3-7 years. Depending on the water chemistry and water usage.
3. A common problem with this venturi style also is oxidized iron and manganese plugging up the water line from the venturi nozzle to the bladder/well tank, aeration tank, and/or filtration tank causing severe pressure loss.  This requires annual or semi-annual maintenance to clean out the lines and flush the well tank.  Consequently, the lack of household water pressure and water volumes necessary to efficiently operate a home is a problem. So this style system is rarely used now.

Venturi Nozzle

 2 Tank Aeration Filtration system

This "Two Tank" style Aeration system has been popular for a very long time and was the next generation after the Venturi style. The first tank or "Contact Tank" has air pumped into it with a small air compressor. This creates "Microbubbles" of oxygen so iron and manganese are oxidized, become a particle, fall out of the water, and then travel to the filtration tank for removal.  Depending on the manufacturer. The system can be programmed to run the air compressor at certain intervals. Example: Every 10 min for 30 seconds. Depending on water chemistry and household water usage. This system is normally set to backwash every night. Small amounts of hydrogen sulfide can also be removed with this method. Generally, 1ppm of H2S or less can be successfully removed depending on the levels of iron and manganese present in the water supply. Higher levels of H2S require chlorination or hydrogen peroxide systems as described above. One of the issues with this style is mud balls developed in the bottom of the contact tank and the valve heads would become plugged with iron. This style of filtration system typically needs to be rebuilt and the filtration media replaced about every three years, depending on the water chemistry and water usage. These systems use a "Multi-Media" filtration pack as the filter media. This would need to be replaced at those same intervals and have the contact tank flushed. Causing this system to be rather a service-intensive and expensive proposition to keep rebuilding.

Single Tank Aeration Filter System

The newest generation and, in my opinion, the best aeration filtration system, is now a single-tank filtration system. It is very simple and works extremely well. Air is drawn into the tank during regeneration through a small venturi nozzle that is incorporated into the valve body, this can be cleaned very easily when necessary. This is the same type of process used on water softeners to draw brine. With the electronics available now, especially on "Clack" valves, each system can be custom-programmed for every household. Allowing for greater flexibility in setting up the system for water chemistry, draw time, and backwash lengths. The Clack valve also runs according to gallons or a day override to ensure you have filtered, conditioned water even during peak periods of water usage. This diagram shows most of the oxidation of iron, manganese, and hydrogen sulfide occurs in the upper third of the tank. But the whole tank is flooded with oxygen so the oxidation process happens all through the filter media bed. This system typically regenerates every 2-3 days or by gallons used. Whichever comes first.

When using any filtration system bed depth and contact time is of the utmost importance. Oxidation and filtration of iron, manganese, and H2S can take some time so it is generally better to have a taller tank, such as a 10x54 or 13x54 for residential use to allow enough time for this whole process to work effectively. The higher the iron and manganese levels are the larger the size tank is required to work effectively and have a longer lifespan. Larger filter tanks like a

Duplexed backwashing filtration system

13x54, along with duplexed or triplexed filter tanks should be considered with iron levels above 5ppm and manganese levels above 2ppm. Especially with households that use high volumes of water. Water pressures of 30psi-70psi are optimal for proper backwashing and cleaning of the filter media, no matter what type is used. Filter systems require at least 5gpm to backwash properly. Larger systems may require 7-10gpm, depending on the filter media used. The good news is these systems can filter down to 5 microns meaning they are very efficient at the filtration of fine particulates.

Pros:  The Aeration process is the simplest method and, with a single-tank aeration system, requires very little maintenance. Many different options for filter media are available to accommodate your particular water problems.

Cons:  Aeration systems are not for use with high levels of hydrogen sulfide or iron bacteria. High levels of dissolved oxygen, with an aeration system, can cause copper corrosion.

To summarize: Every water treatment problem has its own unique solutions. To find your solution start with a complete water analysis to determine what's in the water first and then you can begin to address the proper solution for your home.


I wish you Good Days and Good Water!

Ray McConnell,
The Water Softener Blog


Below are links related to the topics discussed in this article.

Water Testing: Water Check

Find a Certified Water Treatment Dealer in your area

Selecting a Home Water Treatment System

WellOwner.Org

How the Oxidation and Filtration process works

Water Filter Media Guide

Water Treatment Manufacturers:
Hellenbrand Water Treatment
Water Right Inc.
Nelsen Corporation

Clack Corporation

Fleck Water Treatment by Pentair


© Copyright The Water Softener Blog. All rights reserved

How Water Softeners Work.

Water softener systems are basically an appliance that treats incoming water to the home to remove hardness minerals (Calcium, Magnesium) present in water and provide softened water for the home to protect plumbing fixtures and water-using appliances to prevent hard water scale buildup and iron staining. Making the home run more efficiently.

Water softeners/conditioners are not the solution to every water treatment problem. There is a myriad of water chemistry problems such as high iron, manganese, hydrogen sulfide, and low PH along with many other water problems that require different types of water treatment equipment to correctly treat the water.  The first step in determining the proper water treatment solution is a complete water analysis to determine the hardness, iron, and other water chemistry issues that may need more treatment than a water softener.

Water softeners have six main components:

1. Control Valve
2. Distributor Tube
3. Water Softener Tank
4. Water Softening Resin
5. Brine / Salt Tank
6. Float Assembly

Water softener regeneration cycles:
1. Backwash
2. Brine draw
3. Slow rinse
4. Fast rinse
5. Brine refill
6. Service

Water softeners have to run/regenerate at some point to rinse off the hardness minerals the resin has collected and restore the sodium charge on the resin beads.  The regeneration cycles shown above are the most commonly used but may vary in their sequence depending on the particular water softener and manufacturer.  When not regenerating a water softener is normally in service mode.

Ion Exchange Process:  Sodium Chloride or Potassium Chloride (Water softener salt) is used to regenerate the water softener resin beads during the brine draw/regeneration cycle. Sodium or Potassium displaces the hardness minerals the resin has collected during the service cycle and the hardness minerals are flushed to the drain.

Resin Regeneration Process

Water Softener Resin Comes In Many Color Variations

Polystyrene Water Softener Resin

Every water softener has a given amount of "capacity".  The amount of resin in the softener tank and size of the softener tank determine the total capacity and how many gallons of water can run through the water softener before it has to regenerate.
For example, a 9x48 water softener tank will have about 30,000 grains of capacity (1 cu ft of resin) and a 10x54 tank is about 45,000 grains of capacity (1.5 cu ft of resin).  Single tank water softeners, such as the Fleck 7000 above (Blue Tank), are factory set to regenerate at 2 o'clock in the morning (This is referred to as delayed regeneration) and will take anywhere from 60 minutes to over 2 hours for a complete regeneration cycle. Depending on the capacity and size of the water softener. A certain amount of resin is always left out of the total equation to have a little extra capacity on days with heavy water usage. This is referred to as the "Reserve". Typically one full day of water use is left as the reserve.


Older water softening systems operated on a "Time Clock" basis

Fleck 5600 Valve with a 12 Day Time Clock

and ran a certain number of days per week based on how many pins were set for days to regenerate. Time clock systems have 6 to 14 pins that determine how often it runs/regenerates.  These time clock model water softeners were very inefficient and frequently ran out of softened water when the capacity was exceeded. Which was usually on weekends when we all use 2-3 times the water than during the week. When a water softener runs out of capacity the resin is exhausted of softened water causing hard water to service. With a time clock water softener, there needs to be at least one day's water usage left in reserve to prepare for those heavy usage days. With more modern water softeners reserve capacity is not as important because they are constantly metering the water usage and adjusting the regeneration cycles to accommodate the changing water needs (depending on the manufacturer and model).

Modern water softening systems regenerate on gallons used and are much more efficient as they only regenerate when needed and tend to have better consistency of softened water.
There are basically three types of water softeners "Cabinet Models", "Single Tanks" and "Twin Tanks".  A single tank water softener refers to any water softener with one softener tank and a salt tank.  This may be one as shown at the top of this article (Fleck 7000) or what is referred to as a cabinet model (Shown here on the right) where the water softener system is built into the salt storage tank. Cabinet model water softeners tend to be the least expensive, and are installed by many DIY'ers but also tend to only last 3-7 years so you get what you pay for with this style softener.  They also tend to be very inefficient at removing iron from well water.

An even more efficient option for your water softening system is a "Twin Tank" water softener as 

Twin Tank Water Softener

shown here. This style water treatment system actually has two water softener tanks.  One tank is in service (supplying soft water) while the second tank is in standby.  This type of water softener is a true on-demand water treatment system. When one tank becomes almost exhausted of softened water it regenerates immediately and switches to the standby tank that goes into service. Twin Tank softeners normally regenerate during the day when water is being used.  Twin Tank systems use a portion of softened water from the second tank to clean the tank that is being regenerated so they tend to be very efficient at salt usage, iron removal, supply the best quality water, the most consistent quality of softened water and have fewer service issues because they are regenerating with clean/soft water.

For the best, durability, serviceability, reliability, longevity, and quality of water, I recommend a separate water softener and brine tank system.  A separate water softener and salt storage tank can last well over 20 years.  If you decide to install your own water treatment system it pays to consult with a local plumbing supply house or local water treatment company that sells "cash and carry" water treatment systems, (NOT the box stores).  They can be a valuable resource to help you choose the proper system, setting it up, future technical/service support, and test your water to find the best water treatment system to treat your water.  Having a water analysis done by an independent water testing lab is also a good idea.  An independent lab can test for bacteria, arsenic, lead, and other concerns that a plumber or even a water treatment company would not normally do.  A thorough water analysis from a licensed lab can be a useful reference for the future.  If you seek help from a professional water treatment company be sure to check them out thoroughly online.  Angie's List, Google Reviews, Yellow Pages, Yelp, and various other sites can be valuable resources to check their work, reviews, and customer satisfaction.  There is a lot of advice online from so-called water softening sites and experts but I have found much of the information to be very misleading and quite often just uninformed advice from people who have never been in the water treatment business.

I hope this information and future blog articles can assist you in your search for the proper water treatment system for your home and family.  If you do choose the proper water softener system for your needs and maintain it properly there is a good possibility of it lasting 20 years or more.


I Wish You Good Water and Good Days!

Ray McConnell
The Water Softener Blog


More information is available regarding topics of this blog in the links below:

How Softeners Work - YouTube

Water Softener Facts

Wikipedia - Water Softening

Whirpool - Water Softener Basics

Water Softener Salt

PSU Extension - Water Treatment

© Copyright The Water Softener Blog. All rights reserved

"Water Filters" part 1 - When, What, Why and How to use a whole house water filtration system.

"Water Filters". Water filters cover the gambit from simple faucet filters, refrigerator filters, in-line filters to filter housings with a replaceable filter cartridge to all types of whole house backwashing / regenerating filtration systems that remove, iron, odors, manganese, radium, lead, turbidity and a plethora of other water problems.  This subject covers such a wide range of water problems it could take many blog articles to cover just the basics of water filtration.  One thing I know for certain though is what the typical consumer considers a water filter and what a water treatment professional would consider a water filter is totally different.

In the first "Water Filters" article we will look at filter housings and filtration cartridge options.  Water filters installed for the whole house are called, Point of Entry (POE).  Water filters used for specific locations, like under a kitchen sink, are called, Point of Use (POU).  The most basic filtration is a filter housing with a replaceable filter cartridge.

Filter housings come in almost any size for many different uses.  A standard filter housing for residential whole-house use would be 3" x 10" (lower left in the picture) up to 4" x 20" (upper right in the picture, here).

The problem is these replaceable filter cartridges are sold everywhere for rust, sediment, odor, and chlorine removal for water.  Although they will definitely help reduce those things, depending on what filter is used, cartridge filters are not always the best options to do so and can plug up quickly causing replacement of filters frequently.  This can become an expensive proposition as filter cartridges vary from a few dollars to over a hundred dollars.  They can also significantly reduce water pressure and water volume.  These style filters were very popular when well casings were steel.  With steel well casings, scale, sediment, and rust commonly come off the inside of the well casing causing service issues with water treatment equipment.  Cartridge filters, before a water softener, were a necessity to remove any sediment from this type of well.  Today most drilled wells use PVC casings so scale and sediment issues have generally been resolved to the point where filter cartridge housings typically are no longer necessary.  A good example where such filters are still an economical choice with good results would be the water issues in Flint, MI.  Using a simple filter housing, with a block carbon filter, under the sink and tied into the kitchen cold water will greatly reduce the lead content, chlorine, and turbidity issues for drinking water.  However, the filters would need to be replaced frequently, depending on how much water is used and the incoming water quality.

Replaceable filter cartridges are rated by "micron size" and/or specific contaminant removal.  Filter cartridges come in micron ratings from .35 mic, to .5 mic. 1 mic absolute on up to 50 microns.

 Cord wound, Pleated, and Polyspun Filter cartridges

Examples:
1.  A 10-50 micron sediment filter may be used before a water softener.
2.  An activated carbon filter may be used for chlorine reduction.
3.  A dual gradient filter such as a DGD 2501 removes larger particles on the outside (25 microns) and
increasingly smaller particles as it passes toward the center of the filter (1 micron) and is generally used as pre-filtration for laboratory use, machinery, and reverse osmosis systems.

The specific filter you may need depends on the water problem that needs addressing.  If it's for sediment removal, before a water softener, I would recommend a 20-50 micron sediment filter preferably in a 4"x 10" or 20" BB housing. Cord wound, Poly spun, or Pleated filter cartridges are recommended for sediment removal.

There are many types of carbon and carbon filters for different water problems. As discussed earlier block carbon filters are frequently utilized to reduce lead content in drinking water.  Another concern with municipal water supplies is "Chloramines" which are a combination of chlorine and ammonia additives added to municipal water supplies for disinfection.  There are specifically formulated carbons to remove chloramine from your drinking water.  Before using any filter for specific drinking water issues check the NSF guidelines for filter certification based on particular contaminant removal.

Block carbon filters 

Filter Changing Tips:
 1.  Always change filter cartridges at regular intervals.  Change the whole house filters every three months or sooner depending on the water quality and the amount of water used.
 2.  If you find you have difficulty removing the filter housing initially. Make sure the incoming water is off.  Open a nearby faucet to relieve the water pressure, hold the pressure relief valve down, close the outlet valve when the housing is loose, and remove the filter housing.

3.  Change the filter housing o-ring annually and use only silicone lubricant (never vaseline).

4.  Clean and wipe off the filter housing threads, on the housing and inside the head, at every filter change, and never lubricate the threads.
5.  Clean and sanitize filter housings whenever changing filters.  Simply wipe out the filter housing, add a small amount of household bleach (tablespoon), rinse the housing out, and install a new filter cartridge.
6.  When tightening the filter housing "never use a filter wrench".  Hand-tighten the housing only to seat the o-ring.  Using the wrench will flatten the O-ring causing it to leak and make even harder to get the housing off next time.
7.  When replacing the filter leave the water valve on the outlet side of the filter off.  Turn the water on slowly to the filter housing while holding down the pressure relief valve to release the air from the filter housing until all air is released then open the incoming water valve all the way. If there is no pressure relief button open a laundry tub faucet while turning the water back on to the filter to bleed the air off.

4" x 10" Big Blue Housing with a red pressure relief button.

There is also another class of whole house sediment filters commonly known as a Rusco or Blow Down filter.  These filters have a screen inside to filter sediment, sand, and debris from wells.  These types of water filters can be cleaned by opening a valve at the bottom and "blowing down" the filter periodically. Every 2- 3 months normally. These filters are a frequent choice for well drillers when sand is a problem coming from a well.

Rusco blow-down filter

*Warning: Never use a cartridge filter for drinking water on a non-potable water supply.

A small sample of filter housings and cartridge filters are available.

When installing a filter housing, for any purpose, it should always be mounted securely to a wall for ease of changing filters and to protect the plumbing along with shutoff valves before and after to isolate the housing when changing filters.  Some filter housings incorporate a built-in shutoff on top and a pressure relief valve to aid in the filter housing removal and filter change.

A properly installed prefilter housing before a water softener

In our next blog regarding "Water Filters", we will discuss whole-house filtration systems using backwashing filters and automatic regenerating filter systems to remove everything from sediment to iron, odor, arsenic, radium, and more.


I wish you, Good Days and Good Water!


Ray McConnell,
The Water Softener Blog

Below are links related to the topics discussed in this blog article;

What is a filter micron rating?

NSF - Contaminant Guide

What do carbon filters remove?

What are chloramines?

Pentair Water Filtration

Wiki How - Choosing a home water filter

WQA - Perceptible Water Quality Issues


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