How to Remove Iron from Water in Your Irrigation System

Installing a high-quality drip irrigation system is the first step towards a lush, flourishing agricultural field. To maintain healthy crop yields and preserve soil nutrients, you must consistently monitor the water quality in your irrigation system. This ensures that there is no excess or deficiency of minerals that may negatively affect the health of your crops.

Specifically, too much iron in an irrigation system can risk the growth of your greens by potentially blocking the irrigation system. Research suggests that even as little as 0.3 milligrams per liter of iron in water can stain everything it touches, from plants to pathways.

So, how do you get rid of iron in your irrigation system? Let's find out.

Common Signs of Iron in Your Water

As a general rule of thumb, you should assess the water quality of your irrigation system every 2-3 years to spot potential signs of contamination. Here are a few common water issues that may indicate the presence of high iron levels:

• Yellow, brown, or orange stains on plants, fences, or pavements
• Clear water that runs reddish or brown when exposed to air (ferrous iron)
• An earthy smell or a metallic taste may suggest high iron levels.
• Frequent clogging of irrigation nozzles and sprinklers

What Are the Types of Iron in Water

When dealing with iron contamination in irrigation systems, it's essential to be familiar with the types of iron found in water. This will help you choose the proper water purification method.

The iron in your water for irrigation can take several forms, including:

1. Soluble Ferrous Ion (Clear Water Iron)

As the name indicates, ferrous iron is dissolved in water at any pH level and is not visible when the water is first drawn from the pipes and sprinklers. This is why the water containing ferrous ions appears colorless and transparent. It usually becomes noticeable when exposed to air and oxides, turning into a brown and red mineral called ferric oxide.

2. Insoluble Ferric Ion (Red Water Ion)

Ferric iron is iron that has already oxidized and precipitated out of water, which is why the water appears rust-colored when first drawn from the pipes. These ions are suspended in water as a reddish, yellow, or brown tint. Since red-water iron is already particulate, filtering out from an irrigation systemis much easier.

3. Organic Iron

Organic iron is formed when an organic acid reacts with iron, resulting in a brown or yellowish water appearance. When the iron-rich water from your pipes meets organic matter (like decomposing vegetation), it forms organic iron.

Unlike ferric iron, this type of iron does not settle out or precipitate easily since organic molecules stabilize it. It also promotes the growth of iron bacteria under suitable conditions, forming slimy colonies around the irrigation equipment.

Methods to Remove Iron from Irrigation Water

If the iron concentration in your irrigation system is more than 0.3 part per million, it's time to take some measures to improve your water quality. Here are a few methods for removing the iron in your water, depending on the type of contamination.

Filtration Systems

Before you choose the proper method for water filtration, get a sample tested in a laboratory to determine the type of iron contamination. If the water is contaminated by particulate iron (ferric iron), the most effective method is filtration, which helps physically remove iron from water without any chemical additives.

Here are the types of filters you may use:

• Sediment Filters: These filters trap iron minerals in a particulate form that can be seen suspended in the water (ferric iron).
• Oxidation Filters: These filters convert and remove iron in one unit by combining an oxidizing agent with the filtration medium. The filter media is coated with manganese oxide, which converts soluble iron into insoluble iron and then filters it out. The filtered water is free of 75-90% of iron particles thanks to oxidation.

Water Softeners

If the water has a basic pH level (above 7), a water softener won't work well. However, if your water is contaminated by ferrous ions and has an acidic pH level (below 7), opting for a water softener is your best bet.

Using the ion exchange method, water softeners remove ferrous iron by replacing iron ions with sodium or potassium ions. This method is usually used when iron concentrations are lower (under five ppm) and ineffective against ferric ions.

Oxidizing Agents

If the iron concentrations in your irrigation system exceed 10 mg/l, you must opt for chemical treatments to protect the health and well-being of your crops. This is where oxidizing agents come in, converting soluble ferrous iron into insoluble ferric iron, which can then be removed through filtration.

Here are two common oxidizers you may use to get rid of iron-rich irrigation water:

• Chlorine: Known as a powerful oxidizing agent, chlorine forms ferric chloride by reacting with soluble iron salts. Consequently, the microscopic iron molecules stick together and settle down at the bottom, where they are later removed through filtration.
• Potassium Permanganate: It is a strong oxidizer that not only removes iron contaminants but also deals with manganese, converting them into insoluble states. You should employ this method if/when your water has a pH of 7.7 to 8.0.

Magnetic Water Treatment

These magnet devices use electromagnetic fields to change the molecular makeup of various water constituents like calcium and iron to other more "inert" forms. The claimed result is a reduction or elimination of water contaminants.

These devices are magnets or electromagnets attached to waterlines entering homes and businesses to "purify" water supplies.

Aeration Systems

Farmers who want to manage iron levels in irrigation water without resorting to chemicals may install an aeration system. Introducing air into the water, aeration helps promote the oxidation of soluble ferrous iron into insoluble ferric iron. This ferric iron is then much easier to filter out.

This method is great for those who want to monitor their water quality less regularly and apply water softeners or chemical treatments.

The method uses aerators or diffusers to bubble air through the water to increase air-water contact. This helps improve air quality by dissipating gasses like hydrogen sulfide, which often accompanies iron.

Conclusion

By effectively managing iron levels in your irrigation system, you're making a significant investment in the well-being of your crop yields. This practice prevents clogging and ensures your plants receive the highest-quality water, leading to healthier growth and less maintenance. It's a long-term strategy that pays off in the form of more nutritious crops. The quality of water and soil is very important when it comes to crop yields.

This is where DripWorks comes in, a trusted supplier of drip irrigation. At DripWorks, we aim to help you save time, water, and money through clean, green irrigation systems. Using 30% to 50% less water than other irrigation methods, we help farmers achieve sustainable farming and water conservation goals. Give us a call today to learn more about our products and services.