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Rust Stains in Pools - How to Fix

There are 3 reasons why you may see rust in your pool. It might be the start of Concrete Cancer.

1. A metal object like a bottle cap or hair pin has fallen into the pool and has been left sitting in the one spot and has started to rust. This type of rust spot is superficial and is only on the top layer of the pool surface. Most of the time this type of rust spot in pools can be treated by speciality pool chemicals like citric acid or complex stain removers available from most pool shops. Be sure to follow the directions carefully as some of these chemicals require you to lower your chlorine levels before adding the stain remover for maximum effectiveness.

2. The pool water has come into contact with the steel work from a crack or a gap in the concrete shell allowing treated water to come into contact with the steel reinforcing of the pool shell. Often you will first notice this type of rust issue as a small spot that gradually grows over time. You may of tried to remove the rust mark in the pool with pool chemicals as mentioned in point 1 above only to find the rust stain reappearing over time. With this type of rust stain it is far more important to get it repaired as soon as you discover it. Failing to do so can lead to concrete cancer which is when the steel reinforcing swells as it rusts and creates further cracks to appear in the concrete leading to more exposure to the pool water and more expense.

3. Rust Plating. This type of rust stain in pools occurs when there is too much metal in the water. Usually from heavy copper algaecide. Quiet often you will see this happen around outlet jets within the pool and most times in salt water pools. As the pool water passes through the filtration the water flows over the salt water chlorinator cell on is sent back to the pool as chlorinated water. As the water coming out of the jets is high in chlorine when going back to the pool if there is excess metals in the water the metals will plate out on hard surfaces looking like rust. This can be cleaned off with an acid wash and sometimes needs a straight acid mix to remove. It is recommended never to try and remove rust stains in pools with a straight acid mix unless you are very confident that you will not damage your pool surface. Better to leave this method to the professions.



Unlike other pool repair companies Gold Coast Pool Repairs only uses speciality concrete based waterproof structural repair compounds as well as a concrete based flexible waterproof membrane over the top of the base compound to ensure the greatest rust prevention. Note - We never use epoxy products as sometimes they do not adhere properly to the concrete shell allowing water to pass through the patch and come into contact with the steel work again after repairs.

If you need assistance with treating rust spots in pools or require an acid wash we are more than happy to help you out call 0400 310 498

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rust tsain in pebblcrete pool


repaired rust stain in pebblcrete pool


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