How To Remove Iron/Rust From Pool Water?

Remove iron from pool

Well, If somebody tempts you to spend time in swimming pool and then slowly reveal that if you get in, then your hair and nails will be stained, will you ignore and just get in? No, right? Not only you, nobody will like to get into such pools. What is that actually present in the pool that end up in staining you? The answer for all these questions is iron and copper.

Before we talk about how to remove iron/rust from pool water, we should first know about the side effects of having iron in the water. How do you recognize water that has high levels of iron concentration? Let’s discuss about all of them and then briefly find a solution to get rid of high concentration levels of iron in pool water.

What is the impact?

The biggest problem if iron is present in more than adequate quantities in pool water is that they cause stains. Discoloration is very unpleasant to our sight. The water changes its color and will not please the swimmers. However, it will not turn them cloudy.

The coloured water will stain the pool surface at the bottom, walls and not only that, it will stain even the hair and nails of the swimmers.

Imbalanced levels of iron will rust the pool equipment. This corrosive nature will in turn result in releasing unwanted copper metal into the water. So, as a part of pool ﻿﻿equipment, the victims of corrosion will be pool’s pump, pipes and many other metal accessories.

Where does iron originate from?

Iron is the fourth most commonly found metal in the earth’s crust. The metal shines in a beautiful silver shade but when reacts with water and air, it corrodes.

Iron is generally found from fill water. If the source is a well, then the well may contain iron metal in its ionic state. When you purify these water, the metals get collected in the pipe or plumbing network before it reaches the pool. This gradually corrodes the pipelines and other pool equipment through which it passes. This in turn releases copper into the pool water.

If you think that cheap pool equipment will do your work, then you might not be thinking correct. The cheaper ones are made of iron and this will easily corrode very soon down the road.

How to identify?

Usually, you can take your pool water sample to your local pool store and get it tested for iron.

If your pool is having high concentration levels of copper, then your pool looks green. On the other hand, if it has highly concentrated levels of iron, then your pool looks rusty brown.

Again, note in your mind that this is not the same every time. This is generally true in many cases, but when you test the water, you might surprisingly find a different result. So do not come to a conclusion until you test it.

First of all, if iron is present in your pool in normal levels, it is very difficult to identify. But as the concentration increases, the water starts to ﻿﻿﻿﻿﻿discolour into rusty brown. Sometimes, they may turn into bright green or black hue. Obviously, pools filled with such water will not please the swimmers.

Is there a possibility to remove iron/Rust?

The answer is Yes! It is difficult to treat a pool that is rich in calcium, where you need to remove complete water and start over again by taking water from a different source. However, if your pool water is high in iron, you can treat it.

Swimming pool industry offers iron remover that works effectively to deplete iron levels in your pool waters. In many cases, your pool suffers high quantities of iron when the source of water is well. So, in such cases, you can add iron remover while the pool is busy filling up with well water.

Methods to eliminate iron from pool water

To remove iron and other metals from water, you have many solutions but, you should choose the right method only after analysing your pool. For this, you should first get the pool water tested by a lab in pool store.

After they confirm the high levels of iron in your pool water, you can take their guidance for solution.

Let’s discuss about some of the commonly used iron removal methods in detail:

Method-1: Shock treat the pool

Before you go ahead with this type of treatment, it is important for you to consult pool professionals to know which type of shock treatment would be apt for your pool.

Usually, shock treatment is of two types:

After you choose appropriate type of shock treatment for your pool, you should follow it up with clarifier treatmen﻿﻿﻿﻿﻿t so that your pool gets free from iron build up. You need to carefully read the instructions on the shock label.

  • You should first oxidize the metal in the pool. For this, you should shock treat the pool.
  • Once the metal oxidizes, it separates from the water and settles separately like a rust.
  • Since the rust has settled separately, vacuum it out of the pool.
  • Run the pool for 6 to 8 hours while implementing the shock treatment.
  • If your pool ﻿﻿﻿walls are stained, scrub them so that the iron that is stuck to them will loosen and gets mixed with the remaining pool waters that are undergoing the shock treatment.

Method-2: Flocculent method

This method effectively works to give you an iron free pool waters.

  • Before you go ahead implementing this method, you should first backwash ﻿﻿﻿﻿the filter.
  • Calculate how much flocculent you should add. Usually, for every 6,500 gallons of water, it is suggested to add one quarter of a gallon of flocculent.
  • Then, add ﻿﻿﻿flocculent to the waters so that it mixes with the water to attach itself to the iron. Once it attaches to the iron, it pulls the iron to the bottom of the pool. This way, it collects on the floor of the pool.
  • Remove the collected metal on the floor. Since it settles on the floor, it would be very easy for you to remove it.

Method-3: Prevent from oxidizing

  • In this method, you should see that the metal is not oxidized. So, add a chelating or sequestering agent.
  • The added agent forms complexes with the existing metals in the pool.
  • This way, you can prevent the metal from being oxidized.

Method-4: Iron remover method

  • Close the pool to swimmers when implementing this method.
  • Turn on the filter pump.
  • Do not add chlorine so that the existing chlorine levels start dropping.
  • Wait till the chlorine level drops to zero.
  • Now, lower the pH ﻿﻿of ﻿﻿the ﻿﻿poo﻿﻿l. For this, add pH Reducer.
  • Wait till the pH reading reduces to 6.8 ppm.
  • Now, calculate how much you should add ‘Iron Remover’. For every 5000 gallons of water, you should had one quarter of Iron Remover.
  • Let the water circulate overnight.
  • When the water appears clear, increase pH levels to the water such that it reads between 7.2 and 7.8 ppm.
  • Now that your pool is clear from iron, you can start resuming your normal pool maintenance activities like filtering, chlorination etc.

How to prevent from recurring

If the source of water is rich in iron and you are not in a position to find an alternative source to fi﻿﻿ll up your ﻿﻿pool, then you should regularly add sequestering agent or chelating﻿﻿ agent. These agents are also referred to as ‘metal out products’.

When you regularly add metal out products to the pool, any new metal that arrives the pool water from the source will then be held by the pool in an inactive complex.


When you doubt that you pool water has lot of iron, you should first get the water tested by a lab in pool store. Once it is confirmed, the pool professional﻿﻿﻿s can tell you how to remove iron from pool water and can guide you with appropriate iron removal method.

Once you follow a specific method to successfully remove iron from the pool, resume normal pool maintenance activities and at the same time, take measures to avoid the situation to recur.

Usually, the situation recurs when you are unable to avoid the source to fill the pool. In such scenarios, you need not worry if you regularly add metal out products to your pool to keep away metals in your pool.

Bryan Mallory
