How to Remove Rust Stains from Pool Surfaces

Rust stains in pools are a common problem that can be caused by the presence of metals in the pool, typically from metal pool equipment, ladders, or even metal parts in the filtration system. These unsightly stains can turn your pool from inviting to unattractive quickly, but fortunately, with the right tools and methods, you can remove rust stains and restore your pool to its pristine condition. In this post, we’ll cover why rust stains form, how to remove them, and how to prevent them from occurring again.

Why Do Rust Stains Form in Pools?

Rust stains typically form when metals such as iron or copper come into contact with pool water and begin to oxidize. This oxidation process creates the reddish-brown stains that are commonly seen on pool surfaces. Other factors can also contribute to rust stains:

Metallic objects: Common pool items such as ladders, handrails, and even metal pool toys can introduce metal particles into the water.
Water chemistry issues: Pools with imbalanced pH levels, low alkalinity, or high calcium hardness can speed up the oxidation process, increasing the chances of rust stains.
Low stabilizer levels: Cyanuric acid, also known as pool stabilizer, can help prevent metals from oxidizing in your pool. Low levels of stabilizer make it easier for metals to oxidize and form rust stains.

Rust stains can be tough to remove, but with consistent maintenance and the right treatment, you can get rid of them and prevent future issues.

Methods to Remove Rust Stains from Pool Surfaces

If you notice rust stains in your pool, the first step is to determine the extent of the staining and then select the appropriate method for removal. Below are some of the most effective ways to remove rust stains from your pool surfaces.

Use a Pool Stain Remover

One of the easiest and most effective ways to remove rust stains from pool surfaces is by using a specialized pool stain remover.

Choose the right product: Pool stain removers are designed to break down rust and other types of stains, such as those caused by organic material. Many products are specifically designed for metal stains.
Follow the directions: Pool stain removers often come with specific instructions for application. Follow these carefully to avoid damaging the pool surface.
Apply the product: Apply the stain remover directly onto the rust stains. Be sure to coat the stains fully and allow the product to sit for the recommended time.
Brush the area: After the product has had time to work, use a pool brush to gently scrub the area. This helps lift the stain off the surface.

This method is ideal for general rust stains, especially if you want a quick and reliable solution.

Use Vitamin C Tablets

For a natural, cost-effective solution, vitamin C tablets can be used to remove rust stains in your pool.

Place the vitamin C tablet: Simply place a vitamin C tablet directly on the rust stain. Vitamin C is acidic, which helps break down the iron oxide and lift the stain.
Let it dissolve: Allow the tablet to sit on the stain for a few minutes, letting the vitamin C dissolve and react with the rust.
Brush the stain: Once the tablet dissolves, use a pool brush to scrub the area, helping to lift the remaining stain.

This method is particularly effective for small or localized rust stains. It’s inexpensive and gentle on pool surfaces.

Use a Pumice Stone

A pumice stone can be an effective tool for removing rust stains from pool surfaces, especially tiles and the pool floor.

Wet the pumice stone: Always wet the pumice stone before using it to prevent it from scratching the pool surface.
Scrub gently: Use the pumice stone to scrub the rust stain gently. Move in a circular motion to avoid damaging the surface.
Rinse the area: Once the stain is gone, rinse the area to remove any pumice residue.

While pumice stones are useful, they should only be used on non-porous surfaces. Avoid using pumice on vinyl or fiberglass surfaces.

Apply a Metal Sequestrant

If rust stains are a recurring problem in your pool, you may want to use a metal sequestrant as a preventative measure. Metal sequestrants help to bind metal ions like iron and copper in the water, preventing them from oxidizing and causing rust stains.

Follow the instructions: Read the manufacturer’s instructions carefully when using a metal sequestrant, as the required dosage may vary depending on your pool’s size.
Add the sequestrant: Pour the metal sequestrant directly into the pool, allowing it to circulate and bind the metals in the water.
Prevent rust formation: Metal sequestrants work over time to prevent future rust stains by keeping metals from oxidizing.

This is a proactive solution to avoid future rust stains caused by metals in the pool water.

Use an Acid Wash (For Stubborn Stains)

For stubborn or deep rust stains, an acid wash may be necessary to remove the stain completely. However, acid washing should only be done by professionals or experienced pool owners, as it involves handling corrosive chemicals.

Consult a professional: Acid washing can be harsh on pool surfaces, especially if done incorrectly. It’s recommended to hire a professional if you are not familiar with the process.
Dilute the acid: The acid should be diluted according to the manufacturer’s instructions to prevent damage to the pool surface.
Apply carefully: The acid should be applied to the stained areas, and the pool surface should be scrubbed gently to lift the stain.

Acid washing is a last resort and should only be used for the most difficult stains.

Regular Maintenance to Prevent Rust Stains

Once the rust stains are removed, maintaining proper water chemistry and regular pool care will help prevent the problem from occurring again.

Balance water chemistry: Ensure that your pool’s pH, alkalinity, and calcium hardness levels are properly balanced. A balanced pool will reduce the chances of rust formation.
Add stabilizer: Use cyanuric acid (CYA) to stabilize the chlorine in your pool. This helps prevent metal oxidation and rust stains.
Clean the pool regularly: Remove debris from your pool regularly to reduce the chances of rust-forming materials coming into contact with the water. Clean skimmers, filters, and pool equipment as part of your regular maintenance schedule.
Store metal objects properly: Remove any metal objects from the pool when they are not in use. This includes ladders, railings, and toys that could introduce metal particles into the water.

Regular maintenance is key to keeping your pool free from rust stains and other contaminants.