Will A Sand Filter Remove Iron from Pool Water?

Tell me one more relaxing thing than swimming in the pool when it’s hot outside. You didn’t find anything that compares, right? That’s because pools are an amazing way to cool off in the summer and add a cute look to your house.

While it’s awesome having a pool, sometimes it can be a hassle to maintain. This is because pool water can quickly become dirty or contaminated, so ensuring the water is clean and healthy is a must for homeowners.

Unfortunately, most homeowners, especially those who’ve just gotten a pool and are still learning the ropes, don’t know how to deal with a dirty pool. It’s tricky to figure out what’s making your pool dirty, especially if you frequently clean it.

Well, pool water can get dirty from the chemicals you’re using and even the tiles/pipes it contacts. But some chemicals and metals can contaminate pool water, so finding the culprit is important.

Often, your pool water becomes murky or dirty because of iron. Most people think iron is safe, so they’re surprised to learn it harms their pool. But excessive metals and minerals can be severely harmful, even when they’re useful in controlled quantities.

So chances are, your pool water is dirty because of iron. And if that’s the case, it’s important to quickly remove the iron to prevent further damage.

Filters and Iron Removal

Now the easiest way to remove the iron is to get a filter. The most common filter for pools is a sand filter.

Sand filters are worth every penny; they remove minerals and chemicals and require minimal maintenance. Thanks to their effectiveness, they’re the filters most pools use.

However, some sand filters can only remove select minerals and contaminants, so you’re only sometimes sure if your pool is as clean as it looks. And if your pool has excess iron, even with a sand filter in, you might need to switch filters.

We’ll discuss if sand filters can remove iron from your pool, but let’s discuss iron and its effect on your water and why it’s so important to remove it.

How Does Iron Get in Pool Water?

Iron can leach into the pool water from poles and metallic tools. However, several water bodies have naturally high iron content, so your pool water might get iron from them.

Most people don’t know iron is always present in your pool water. Like most chemicals and minerals, we can tolerate a healthy amount of iron in water.

However, excessive iron can become a problem because it interferes with water quality. Iron can also react to chlorine, so removing it from chlorinated pool water is important.

What Happens When Your Pool Water Has Iron?

Iron isn’t dangerous, so nothing serious might happen if you swim a lap or two in iron-rich pool water. However, frequent dips in iron-rich pool water can dry your hair and skin, making them coarse.

So basically, iron in pool water is harmful in the long run.

The real problem with iron in pool water is its ability to stain. Iron will easily stain pool water, but it can attract different metals and minerals.

Iron can peel off or corrode metallic coating from tiles and poles, so your pool water might be getting contaminated by the second. The longer the iron stays in your pool water, the more hazardous it could become due to other metals.

Some research also suggests the presence of iron attracts bacteria like E. coli.

Spotting Excess Iron in Your Pool Water

How do you know your pool has iron? Typically, you’ll see the pool water staining. But many metals can stain water similarly, so recognizing what you’re dealing with can be confusing.

A couple of signs tell you if your pool water has iron. Here are some of them:

●  Brown-Rust Tint

Iron can give your pool water a reddish-brown tint, similar to rust. Typically, you’ll find the entire pool turning a light red; this is when you can surmise your pool has too much iron.

However, the red-brown tint might also appear in spots scattered around the pool.

●  Bright Hue

Sometimes, iron in pool water can give it a bright green or orange-red hue. Green pool water can also indicate algae, so it might not always mean there’s iron.

However, the green color given by iron to water is quite bright, so you might be able to tell it apart from algae.

●  Coarse Skin

Your pool might have iron, even when the water appears clear. You might not notice iron in the pool if it isn’t colored, but you can check how the water affects your skin.

Swimming in iron-rich water can dry out your skin or make it feel coarse, so if your hands are suddenly itchy or you’re constantly applying lotion, it might mean your pool needs cleaning.

Another sign your pool water has high iron is if your hair’s suddenly itchy or dry. A sudden and drastic change in scalp texture hints toward a change in water pH.

●  Strange Smell

Is your pool suddenly giving off a strange odor? Does the pool water smell murky or weird?

Changes in the smell of water are a massive sign of contamination. Iron gives water a metallic or pungent odor, so you should clean the pool if you sense such a smell.

Sometimes, swimming in iron-rich water can also give you a pungent or weird smell, which typically goes away when you shower. If you feel smelly after swimming in the pool but don’t have any other BO problems, then you’re probably dealing with a dirty pool.

●  Stains

Iron can stain the pool walls, so you might find spots or stains even after cleaning.

Sometimes, these stains can look like dried blood. This is because iron stains water by creating rust.

How to Remove Iron from Pool Water?

Now that you know how to spot iron in pool water, let’s discuss the common ways to remove it:

Shock the Pool

Shocking the pool means adding chlorine to the water. Pool water is usually chlorinated, but adding chlorine can effectively kill off any bacteria, microorganisms, or algae.

Shocking the pool is also a great way to eliminate minerals and metals like iron.

However, shocking a pool isn’t always the way to go. Sometimes, the iron in water can react with chlorine, further contaminating the pool.

The iron only reacts to the chlorine when there’s too much of it. Adding a large amount of chlorine to iron water can reduce the concentration, but this is a temporary solution.

You might have to shock the pool before moving to a filter.

Add a Flocculant

A flocculant is a chemical that removes contaminants. A flocculant is like glue; it binds the contaminants into groups or blobs. The grouped contaminants float to the pool surface so you can remove them easily.

Naturally, it’s possible the flocculant won’t remove all the iron. This can be a problem when the iron content is too high because temporary removal simply means you’ll deal with the problem once more.

Hence, it’s always best to shock the pool, add a flocculant, and use a water filter.

Use a Water Filter

A water filter is the best and most effective way to remove iron from your pool. There are several types of water filters, but you can easily find one built to remove iron.

Finding a water filter that specifically removes iron is cost-saving and smart because you won’t have to worry about dealing with iron-rich water again. Plus, most filters that remove iron also eliminate harmful bacteria and microorganisms, so you get your money’s worth.

Although most water filters can remove iron, not all are suitable for a swimming pool. Sand filters are perfect for pools; they easily adjust to the setting and remove most contaminants, so let’s discuss them further.

How Do Sand Filters Work?

A sand filter is a big tank with layers of sand in it. The separated layers catch and filter the debris and contaminants from the pool water.

Sand filters are connected to the pool’s filtration network. The position of the sand filter depends on the length and type of your filtration network.

The water from your pool rushes into the sand filter within the filtration network. Here, the sand filter separates contaminants in its layer; the first few layers catch debris and dust, and the water moves until finer particles remove microorganisms.

The filter backwashes the water to preserve purity, from where it returns to the pool. Conventional sand filters need to be manually backwashed, but there are better and modern models with automatic backwashing. You won’t have to handle the hassle of handling water filtration with an automatic sand filter.

Can A Sand Filter Remove Iron from Pool Water?

A sand filter is one of the most effective filters for pool water because it can remove most contaminants and is low-maintenance. That being said, a sand filter may not remove everything.

This is because while sand filters are effective removers, there’s a limit to what sand can remove. Most sand filters can remove dust particles, microorganisms, and even some chemicals, but removing dissolved components is difficult.

Iron typically dissolves in pool water, but luckily, sand filters can remove it. It takes a few chemical reactions to separate iron from water, but it’s not a problem for a sand filter.

The real question is: can a sand filter effectively remove iron from pool water, or will the problem resurface? Let’s find out.

Is it Effective?

A sand filter is quite effective, so you won’t have to worry about the problem resurfacing. Most sand filters can remove contaminants, dirt, debris, algae, microorganisms, and metals like iron and manganese.

However, the effectiveness of your sand filter depends on the type.

A high-rate sand filter uses sand as its filtrating medium, while a rapid-rate filter uses sand, gravel, and rocks. We can’t say one filter is better, but most pools use a high-rate sand filter.

Some sand filters contain meshes or layers designed to remove specific contaminants. A manganese greensand filter removes manganese and iron, so it’s best to get this one. 

How Does Sand Filter Remove Iron?

The water passes through the layers of sand, from where the filter removes all contaminants. During backwashing, iron, manganese, and similar minerals and metals separate from the filtered water and are rinsed out.

This separation is possible thanks to the greensand layer in the filter. Greensand enables chemical reactions to convert iron into removable compounds. During this process, the filter also removes manganese. 

The Limits of A Sand Filter

There are particular cons to using a plain sand filter to remove iron. Let’s discuss these in detail:

●    Excess Waste Water

Using a sand filter creates a lot of dirty wastewater with all the removed contaminants. Not only is handling this contaminated water difficult, but it’s also dangerous to keep.

The contaminated water contains harmful chemicals and debris that can seep into the ground, so you must dispose of it.

●    Partial Removal of Iron

While a sand filter is the best option to remove iron from water pools, some filter models are generic and can’t do the job.

You need to get a greensand manganese filter; otherwise, you might have to experience partial removal of the contaminants.

●    Limited Removal Capacity

A generic greensand filter removes up to 15-20 mg of iron per liter. While this is an impressive quantity, a single greensand filter won’t be enough if your water has too much iron.

It’s best to contact a professional and get your water tested. A water testing kit will reveal how much iron is in your water and what filter is best.

What is the Best Filter to Remove Iron from Pool Water?

A greensand manganese filter is a great option to remove iron, but it has limits. While we suggest getting a greensand filter to tackle the iron in your water, there are other options you can look into.

Air-Injected Iron Filters

Some filters, like an air-injected iron filter, are designed to remove iron and similar contaminants.

The air-injected iron filter draws air into the water to separate the iron. It converts the iron into a solid form by a chemical reaction, so it’s easier to remove.

The solidified iron moves into a mesh filter, from where it can be removed completely.

Chemical Injection Iron Filters

Chemical injection iron filters work similarly, except they use chemicals. The injected chemicals interact with the iron and remove it.

While these iron filters are a great option, sticking with a greensand iron filter is best. Greensand iron filters are excellent removers and do the work without relying on chemicals or harmful components.


Iron is naturally present in most water pools, but its excess can be highly dangerous. Excess iron can alter water quality, damage pool materials, and even affect your skin and hair.

Removing excess iron is important because the longer it stays in the pool, the higher the chances of attracting bacterial growth. Luckily, you can rely on filters to remove iron from pool water.

A sand filter is the most common and effective filter to remove iron from water. A sand filter uses layers of fine sand particles to remove debris, dust, algae, microorganisms, and metals. The removed contaminants rinse out after backwashing.


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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