Iron is the 4th most abundant mineral in the earth’s crust. It is everywhere in our environment. Iron is a major issue for those people who are getting home water supply from well water. In this article, we discuss in depth about what is an iron & how to remove iron from well water.
iron is also the most common issue for homeowner with well. Best iron filters for well water plays an important role to remove iron from well water.
Do you know?
Even low concentration of iron present in water supply is enough to create reddish stains in bath tubs, sinks & laundry. It is very difficult to remove.
Additionally, Hard deposits of ferric(Fe+3) iron will also damage your water supply equipment.
- How Does Iron Get into Well Water?
- Effects of Iron in Water:
- Types of Iron Found in Water:
- Water Treatment For Iron Removal:
- #1. Iron Concentration [<2 ppm]
- #2. Iron Concentration [Between 2-3 ppm]
- #3. Iron Concentration [>3 ppm]
- Filter Media for Iron Filter:
- Can a Water Softener Remove Iron?
- How to Get Rid of Bacterial Iron?
- Frequently Asked Questions:
How Does Iron Get into Well Water?
When rain water falls on the soil it will penetrate the first layer of the earth’s surface. Iron which is present in the earth’s crust dissolved with the water & settles down with ground water.
Concentration of iron in well water may vary depending on the geological condition of the region. Normally, Iron concentration found in well water is between 0.3 to 10 ppm in United States.
Effects of Iron in Water:
Iron is a nuisance and if you have as little as 0.3 ppm (parts per million) in your water,
- Change the taste of water & food gives unpleasant metallic flavor
- Turn your hair, skin & clothes orange
- it’s staining toilets & fixtures
- Damage water supply equipment
- change the test & odor of water
Well, let me put that in perspective. If you had a million balls and only one third (1/3) of that was iron, that would be enough to stain the fixtures in your house, so it doesn’t take much iron at all to cause problems.
So, This is the reason why most of the people that have iron in their water, want to remove it out from the water.
However, It’s not really a health concern when we are talking about iron present in drinking water. In fact, iron is part of a healthy diet.
Overall, iron is a nuisance and it’s so much better if we get the iron out.
Types of Iron Found in Water:
There’re four types of iron found in water
- Ferrous iron (Fe+2)
- Ferric iron (Fe+3)
- Bacterial iron
- Organic Iron
1. Ferrous Iron(Fe+2):
Ferrous iron is also known as dissolved iron in chemistry. It means water looks crystal clear in the presence of it. This type of iron is invisible in water but you can see the negative effect of it.
You can’t eliminate ferrous via filtration system because it is filterable. It will easily pass through the filter. so, to remove the ferrous iron you must convert ferrous iron into ferric iron by oxidation process then pass through the filtration system .
2. Ferric Iron(Fe+3)
Ferric iron is also known as insoluble iron. When it is present in water gives the reddish-orange hue to water. it’s a solid from of iron. it’s actually a filterable particulate.
You can filter it out from water through filtration system.
3. Bacterial Iron
Have you ever noticed?
When you lift the top of the tank of your toilet you can see some orange slimy sticky material floating around, it is called iron bacteria.
This is a small types of microorganism that lives in water using ferrous iron as a food. it creates this nasty, slimy orange color stuff that is very hard to get out.
4. Organic Iron:
This type of iron generally found in shallow wells. It is produced by reacting with naturally occurring acid & organic matter.
Produced organic iron compounds are complex & heavily colored which is responsible for severe staining. This is very stable compound & not allow iron to freely react. Organic iron is very difficult to remove from water.
Water Treatment For Iron Removal:
In order to remove iron from well water, you must take decision based on concentration of iron present in water.
First, you must do a iron test of your water. Don’t skip this step.
Iron tests available either in test strips or in a chemical titration type home test that you can do yourself.
Water Treatment for iron is divided in three parts based on the concentration of iron present in water.
#1. Iron Concentration [<2 ppm]
If concentration of iron in your supply water is less than two ppm then water softener is the perfect choice for you.
You might be able to get the iron out with an ion exchange water softener. It’s one of the cations, and it will be attracted to the resin in the water softener.
Basically, water softeners are designed to remove hardness producing salts calcium & magnesium from water.
Water softener contains cation resin in sodium form. This resin is capable to remove mainly calcium & magnesium ion from water & in addition to that it can remove iron(Fe) if it is present in low concentration up to 2 ppm.
As long as we’ve got enough hardness to have a nice ratio between iron and hardness, we’ll be very successful at removing the iron with a water softener, and that’s the easiest way to get it out.
A water softener is not very effective for water in that the concentration of iron is more than 2 ppm.
#2. Iron Concentration [Between 2-3 ppm]
Iron Removal Filter
When concentration of iron in water is between 2 to 3 ppm then iron removal filter is the best solution for you.
This type of Iron filters contains three filters & the process is called three stage filtration system.
1st filter, made with multi-layer filtration technology produces less clogs & minimum pressure loss.
2nd filter, Carbon block filter made with high quality coconut shell carbon for maximum filtration efficiency and filter life.
3rd filter, Iron-manganese filter capable to reduce iron level from 3 ppm to 0.01 ppm & manganese level from 1 ppm to 0.01 ppm.
#3. Iron Concentration [>3 ppm]
In appearance, Iron filters looks same as water softener but it works based on the principle called oxidation. Here our major concerns is ferrous iron, it is dissolved form of iron so that it can easily pass through any filter.
In oxidation process, iron is converted in to ferric iron by oxidizing it.
Once iron converts into insoluble ferric state it can easily pass through variety of filter media before final outlet.
Oxidation of Iron Methods:
Oxidation of iron can be done in many way but the most common three methods are air oxidation,oxidation using media & chemical process.
Method#1 Oxidizing Agent + Filter Method:
This system combination can easily handle iron level up 10 ppm. It is the cheapest way to remove iron from well water.
In this method, oxidizing agent added to the feed water though pump. After that approximately 20 minutes retention time given to the water in separate tank (for home it is called pressure tank)for precipitating & settling of iron.
Lastly, Water pass through manganese green sand or activated carbon filter to remove iron from water.
Method#2 Air Injector + Filter Method:
This system combination can easily handle iron level up 30 ppm.
This method uses pressurized air to oxidized soluble ferrous state into insoluble ferric state so that it can be filtered easily.
Air injection vessel contains air,water & filter media. When water passes through this vessel pressurized air converts all iron into ferric iron then filtered through media where it can stay & clean water pass through it.
The ferric iron which is stayed in media drained by giving back wash to the filter.
Method#3 Chemical Feeding Method:
In worst scenario, when iron bacteria present in water & iron filter, water softener methods aren’t very effective.
Generally, this method is applicable at well water supply facility.
Some specific chemicals are feed in to the well itself to eliminate, oxidize & disinfect the contaminant with in well water supply.
The most common chemical used in this method are:
- Citric Acid: To decrease the pH of water
- Sodium Carbonate: To increase the pH of water
- Chlorine: To kill bacteria & oxidizing the iron
- Hydrogen Peroxide: To remove hydrogen sulfide & oxidizing the iron as well
Filter Media for Iron Filter:
When it comes to choosing a filter media for iron removal each type of media has it’s pros & cons.
Manganese Greensand Filter:
Manganese greensand is one of the oldest oxidizer used to remove iron from water. it uses a real powerful oxidizer called potassium permanganate.
Similarly, like water softener, the system regenerates and draws some of that oxidizer, the potassium permanganate, up through the manganese greensand media. It is very effective method to reduce iron.
Greensand is also effective to oxidize hydrogen sulfide & manganese. There is also a alternative available to regular greensand called synthatic greensand. It is very lighter & required less frequency of backwash.
- pH : 6.5 to 8.8
- Iron Levels : Up to 15 ppm
- Water Should not contain tannis
The next thing that we use often is a media called Birm, and Birm is just another oxidizing-type media. It doesn’t require an oxidizing agent, but it really requires that high pH and high level of dissolved oxygen.
Sometimes, we’ll mix calcite with the Brim so that we make sure that pH gets increased to help convert that ferrous iron into ferric.
- pH : 7.0 to 9.0
- Iron Levels : Up to 15 ppm
- Water Should not contain chlorine(Cl2)
If water contains chlorine than use greensand instead of brim. Brim filter is long lasting & easy to maintain. It doesn’t required any chemical to regenerate.
Can a Water Softener Remove Iron?
Yes, If iron concentration in water is less than 2 ppm. One thing to keep in mind that an ion exchange water softener does a pretty good job to remove soluble or ferrous iron.
Let’s understand in detail.
Water softener cannot deal with ferrous iron(Fe+2) level >2 ppm.
Very frequently, you hear that where people that have a water softener, but they’re still getting iron stains.They’re still seeing traces of iron in their appliances.
That would be a great indication that there’s ferrous iron is converted into ferric iron in the water prior to the water softeners, and that’s going to pass through the water softener.
Role of pH in Water Softener:
If pH level of water is greater than 8.0 than ferrous iron converts into ferric iron which solid form of iron. It is deposit on resin bed & foul it.
That’s why we always suggest that you put a sediment filter as the very first because it can trap any suspended impurities including ferric iron present in water before water reaches at your home.
How to Get Rid of Bacterial Iron?
If you shock the well with chlorine, a lot of times that eliminates the iron bacteria that’s bonded with the iron, and then you can only worry about the ferric or ferrous type iron.
If it doesn’t go away, that means you’ve got some bacteria in the well that’s staying in there even after a shock. Then, you have to go through probably a constant chlorination process, and then capture the stuff that comes out the other end of our retention tank.
In worst scenario, constant chlorine treatment may be required to disinfect this type of bacterial iron.
In conclusion, to remove iron from water you do a iron test of your water & based on the result pick the best iron removal method that we have discussed above.
Frequently Asked Questions:
How to remove iron from well water naturally?
There is no such thing in existence. If you want to remove iron from well water then either choose a water softener or iron filter based on the concentration of iron present in water
How many types of iron present in water?
There are mainly four types of iron called Ferrous Iron(Fe+2),Ferric Iron(Fe+3),Bacterial Iron & Organic Iron found in water.
Does Reverse Osmosis remove iron?
Yes, If concentration is less than 0.05 ppm otherwise it will foul the RO membrane. Reverse Osmosis System is very effective & proven technology to treat drinking water.