Pool Stains: Guide to Removal

By August 30, 2019 March 19th, 2020 Cleaning & Maintenance
Pool Stains

Stains occur in all pools over time. For that matter, stains occur on all concrete surfaces over time. If you have a pool, stains can be a problem. First, stains can affect the aesthetic appeal and façade of your swimming pool. Second, they may point out premature deterioration of your pool’s surfacing material.  This deterioration may create an abrasion or laceration risk to those swimming in the water. To delay stains in your pool we recommend cleaning service from Pool Troopers, industry insiders with experience in pools since 1952.

If you have a pool, consider this guide to identifying, removing, and preventing stains; maintain a pristine pool at your home with these tips:

Pool Stains

Pool stains can be caused by a range of exposures, elements, and influences; stain removal should begin by identifying what you are dealing with exactly. Typically, there are three types of stains that could affect your pool:

  • Organic pool stains are caused by things in the natural environment, like foliage, algae, or berries.  Do not allow Organic matter to accumulate in your pool. Either clean it yourself or have a professional pool cleaner.
  • Metal pool stains are usually caused by exposure to copper, iron, and manganese, which is introduced through source water or outside factors such as fertilizers and yard sprays.
  • Rust pool stains come from corrosion and foreign metallic objects that are left near or in your pool. For instance, if a hairpin falls off the head of a swimmer, it will sink to the bottom and rust quite quickly. Even the tiny metal clasp on a hair tie or headband can cause a stubborn stain to the bottom of your pool.  Sometimes Rust bleeds through from the rebar in the structural shell of a pool. This is an issue that must be addressed by a pool professional soon rather than later it will not get better and cannot be sealed without tearing that section open and fixing the issue. This is a construction defect and if your pool is still under warranty the builder should fix this for you. 

Also, you may experience waterline stains, which come from oils and lotions, swimmer waste, and from minerals and metals in the pool water itself.

These can range from pink or white in color to gray and black, usually around the waterline of your pool. Talk to your pool supplier and retailer for tips on how to treat these persistent stains.  Many pools in the flight path of airplanes have the notorious black ring around the tile line due to oils and grease from aircraft exhaust. 

Testing Stains

Not sure what kind of stain you are dealing with? It is time to test the stain before moving forward with treating or removing it. First, make an educated guess about the nature of the stain; next, proceed with the following suggestions to further reaffirm or debunk your theory.  Always wear Proper Protective Equipment when testing stains with Chlorinating Compounds and Acid! Eye protection from spills and gloves are a minimum. 

Is it an Organic stain?

The best way to determine if you have an organic stain in your pool, add a shake of chlorine granules to the spot; let sit for 1-2 minutes, scrub vigorously with a brush or applicator. If the stain fades and responds to the chlorine, it is organic; if it does not, it could be a stain caused by metal.  Note: If the chlorine granules cause a stain in your test spot stop, brush them away and add acid to the test spot immediately, you have a metals issue and you just created a metal stain through fluctuation of the pH. 

Is the stain from Metal?

If the stain is not organic in nature, it might be metal; sprinkle some crushed Vitamin C or ascorbic acid on the stain. Does it fade? If it does, it is a metal stain, though it could be caused by rust.

Is the stain caused by Rust?

If you want to determine if the stain is caused by rust, sprinkle some sodium bisulfate on the spot and brush gently into the stained area. If the stain fades, it is a rust stain.

Most pool stains are caused by organic elements, like nature, the environment, and humans that use the pool. Once you’ve identified your stain, you can begin treating it. Still unsure? Call Pool Troopers to take care of testing and removing the stain for you. Haphazardly treating stains in an effort to remove them without first identifying what is causing it may result in damage to your pool that subsequently costs you money in repairs.

Shocking Stains from the Pool

Shocking your pool is an effective way to get rid of most organic pool stains. To do this, you must first test the pH and alkaline levels of your pool’s water. You are aiming for a pH of around 7.0 to 7.2 and alkalinity numbers should be below 80-100ppm, ideally. Reduce the alkaline and pH first, to make the shocking process much more effective.

Next, add a couple of pounds of calcium hypochlorite pool shock to your pool, according to the manufacturer’s recommended directions. Typically, you add a bag to five gallons of water before introducing to the pool.  A few hours after shocking, sprinkle more chlorine granules onto the stains and let sit for 2 minutes before scrubbing the area. Repeat until the stain fades and is removed.

You may also have success removing organic stains by going right to the step of adding chlorine granules to the spot and scrubbing with a brush after it sits for a bit after you have reduced the pH and Alkalinity. Still not removing the stain? Try an enzyme treatment from your local pool retailer or vendor; these can help break down the organic matter causing the stain so that the chlorine is more effective. Ask your pool professional for assistance shocking your pool to remove stubborn stains.

When successful retest the water, and be sure to slowly bring your pH and Alkalinity back up into ideal ranges with Sodium Bicarbonate. 

Pool Maintenance and Stain Prevention

The best way to prevent stains is to maintain your pool with regular and routine service. This is where a qualified pool professional comes in! With inspection, cleaning, and chemical service, your pool professional is able to identify and address any potential problems or issues. This is the best kind of preventative maintenance as you are reaping the benefits of your pool expert’s experience while maintaining a clean pool and removing stains, as needed.

Learn a little more about the role of chlorine in your pool water to appreciate a clean, germ-free swimming pool. In fact, the U.S. Centers for Disease Control and Prevention (CDC) assert that chlorine is key to killing harmful bacteria and organisms that could be lurking in your swimming pool. Rely on chemical service, from a pool professional in the area and know that you are swimming in safe, uncontaminated water.

Testing the pool water and consistency is key in maintaining a safe and clean pool. For chemical service in Florida, Texas, or Arizona, call for more information or to schedule an appointment. Plan ahead as some treatments require that pool owners not use the pool for a period of time after service. Chlorination and proper chemical service are key in keeping your pool’s water safe and germ-free. Don’t risk illness or disease with untreated and dirty water; prevent health risks with regular testing, treating, and cleaning of your swimming pool. Start today. Got more questions? Concerned about keeping your pool as safe as it can be? Call Pool Troopers today for a swimming pool service company that provides chemical service and pool cleaning to pool owners throughout Tampa, St. Petersburg, Sarasota, Fort Myers, Palm Beach, Orlando, Phoenix, Dallas, and Houston. See the full list of locations to find service near you. Since 1952, we have helped pool owners get the most out of their swimming pool with clean, well-balanced water; call to learn more about making your pool a safer, healthier place to be today.