How To Successfully Remove The Stains From Your Pool

After some use, cleaning a swimming pool can become more than just the usual cleaning routine as ugly stains start to build up and occur in multiple places. In addition to looking unattractive, pool stains also make a swimming pool look dirtier, and many people will perceive it that way even if the water is clean. 

There are various causes and types of stain commonly found in swimming pools, these include: 

  • Algae staining
  • Black spot algae
  • Calcium deposits anywhere in the pool including on fiberglass and tiles
  • Copper stains
  • Metal stains
  • Rust 
  • Salt stains

Removing the stains from your swimming pool may seem like a difficult process, however, it is well worth it as pool stains make using your pool less fun, decrease water quality, make your garden look ugly, and devalue your property.

For homeowners or property managers with a pool that is starting to look less than desirable, here is a guide on how to successfully remove stains from a swimming pool. 


How To Successfully Remove The Stains From Your Pool


Diagnose the Problems 

The very first step in removing swimming pool stains is to identify which type of stain it is and what caused it. There are three common types of stain according to which are caused by metals, minerals, organic matter, or rust. To determine which kind of stains are present in your pool, you can examine each stain carefully and take note of their appearance and color. 

Metal Stains

Metal stains are easy to spot as they appear to have either a reddish-brown or very dark color, or the tell-tale look of rust. Different metals cause different color stains: 

  • Copper; teal or turquoise shades of blue-green
  • Iron; rusty red, brown and green-brown
  • Manganese; brown-black or purple 

Rust stains can be a common occurrence, especially in older pools. They are caused by metal objects being left in the pool or cracks in the tiling causing rebar steel underneath to be exposed to water. 

Mineral Stains

Mineral stains are caused by the build-up of minerals, particularly calcium,  which combines with dirt and oils in the water to form a scale film in certain areas of a pool. Typically, mineral stains are found on tiles around the waterline as scaly white deposits, although scale deposits can also cover every surface in a dirty film. 

Waterline Stains

A waterline stain otherwise referred to as a ‘scum line’, is the result of dirt and oils on a pool’s surface combining with other particulate matter to create a film that stains the tiles at the watermark. 

Organic Stains

Organic pool stains are recognizable due to their greenish-brown color and are caused by organic matter getting into the water. When organic matter such as acorns, algae, animals, fruit, leaves, nuts, mud, tree branches, and worms find their way into swimming pools they quickly break down, leaving the water unfit to swim in and likely to cause stains covering most surfaces. 

Metal Stain Treatment

Different metal stains require different removal methods, copper for example is best treated using citric acid, and pool owners can rub and scrub crushed-up vitamin C tablets into copper stains to lighten and remove them. 

Iron stains, however, require treatment with ascorbic acid which involves sprinkling the correct amount of ascorbic acid onto the surface of the pool. The recommended amount of ascorbic acid per 10,000 gallons of water is half a pound. After adding the ascorbic acid, the water filter should be left on a circulate setting for half an hour, this should remove most metal stains, although the process can be repeated if necessary. 

Treating Organic Stains

Newer organic stains are quite easy to remove, however, if organic material is allowed to build up, a swimming pool will develop an all-over brown-black stain which is difficult to remove. 

One option for removing organic stains is to drain the pool and give it an acid wash to scrub and strip the stains away with a brush, this process is very time-consuming and costly, therefore most pool owners only do it every five years. 

Unlike acid washes, enzyme shock treatment doesn’t involve emptying the pool and using harsh chemicals. Enzyme-based pool solutions offer a natural method that is added to water, the enzymes then eat away at the organic matter in the pool, and with some scrubbing the stains can be removed. 

Hire Professional Assistance

For homeowners that are physically unable to clean their pool or who have busy lifestyles, there is the option of hiring professionals that specialize in cleaning pools. Pool cleaning companies bring all the equipment and supplies needed to make your pool look new again. 

A dirty and stained swimming pool makes a garden look unattractive and most guests won’t want to use it, therefore regular cleaning and stain removal is essential. 


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