How to remove pool stains

In this article we will help you work out what type of stain you have, how it occurred, how to treat it and then how to stop it from coming back.

Essentially there are 2 types of stains, Organic Stains and Inorganic Stains caused by heavy metals such as iron or copper.

Organic Stains:

Organic stains in a pool are caused by leaves, algae, or other natural matter sitting on the pool surface. To find out if a stain is organic, you can generally identify if you've had leaves sitting on the bottom of your pool for a while.

Pour some granular chlorine on it and leave for a few minutes to see if it lightens or disappears. If it does, then the stain is organic. To remove organic stains, you need to raise the Free Chlorine up to 5ppm and brush it often, ideally every day. you can also use specific stain removers that contain citric acid.

Pro Tips:

• Remove any automatic cleaners from the pool (the high chlorine isn't good for it!)

• When pouring the granular chlorine on the stain, pour it down your pool pole with the insert removed to accurately land it on the spot you want!

• Check with us to calculate your shock dosage for the treatment.

To stop organic stains from coming back, you can try the following steps:

• Use a Robotic Cleaner to remove leaves & scrub your surface regularly.

• Trim back any nearby trees or bushes to reduce the amount of organic matter falling into the pool.

• Oxidise your pool water to break down organic matter before it can cause stains.

• Use a pool cover to prevent leaves and debris from falling into the pool when it's not in use.

Inorganic Stains:

Inorganic stains in a pool are caused by metals in the water, such as iron or copper.

Iron stains are rare in to come from the town water supply, though can be quite high in those on bore water. To find out if a stain is caused by iron, bring a test into our shop and we can test specifically for high iron levels, this is not a common test so you will need to ask us if you believe you have an iron staining problem. You can remove iron stains with specific stain removers that contain ascorbic acid.

Copper stains, on the other hand, are often caused by over use of copper based algaecides, low quality chemicals such as salt & minerals, mineral systems, ionizers, or other “natural” sanitizers. These can be removed by putting dry acid in a sock and rubbing it on the stain.

Once the stains have been removed from the surface, you will need to add a dose of Pool Magnet Plus or Metal Go to keep the metals “in solution” so it doesn’t form back on the surface.

These products (sequestrants) work by attaching to metal particles in the water, preventing them from sticking to the pool surface and causing stains. However, sequestrants break down over time and require regular additions to maintain their effectiveness in keeping iron or copper particles sequestered and preventing staining.

*There is no practical way to remove iron or copper from the water short of replacing the water with new water that doesn’t have any iron or copper in it.

Pro Tip:

• Drop the pool sock full of dry acid onto the stain & move into position with the pool pole, then leave on until all the dry acid is dissolved moving occasionally.

To prevent inorganic stains from coming back, you can try the following steps:

• Use a metal sequestrant regularly (every 3-4 months) to keep the metals 'in solution' prevent metals from depositing as stains.

• Test your pool water regularly to make sure the pH and total alkalinity are within the recommended ranges.

• Avoid using copper-based algaecides or other products that may add more copper to the pool water.

• Only purchase high quality pool chemicals.

• Consider using a water softener or filtration system to remove metals from the fill water.

• Check your pool heater or plumbing for any copper erosion or corrosion and replace or repair as necessary.

By following these steps, you can effectively treat and prevent organic and inorganic stains in your pool, keeping it looking clean and clear all season long.

Common causes and colours associated with stains.

Party tips for your pool or spa

Making sure your pool or spa is clean before, during and after a party doesn't have to be hard. Before you invite everyone over for a swim, read our tips on getting your pool party ready and know how to get it back in shape once the party’s over.

Before the party

• Ensure your water is balanced,

• Remove all the debris from the pool with a manual vacuum and leaf rake,

• Balance your water, then for a pool give it a shock dose with liquid chlorine or a pool shock sachet (the average size pool is 5 litres of liquid or 500 grams of granular chlorine), For a spa, once balanced, add the recommended amount of a non-chlorine oxidiser as well as removing the cover if you plan to use straight away.

During the party

• If your pool is being used consistently, have the pump running without any automatic cleaner attached to improve water flow and reduce the possibility of damage to your cleaner, always run the spa whilst in use.

• If the pool continues to be used heavily, using a non-chlorine shock such as Oxysheen can be added when there is a short break in swimmer use (like lunchtime) to help maintain clarity and burn off organic swimmer waste.

After the party

• Remove all debris from the pool or spa such as streamers, paper, bottle caps, paper plates, plastic cutlery, etc. If a bottle cap or metal object is left on the bottom of the pool or spa too long, it could stain the surface.

• Clean out all the baskets to improve water flow, both skimmer and pump baskets will have party debris in them.

• Check the pressure in the filter and if it is not too high allow it to filter for another 24 hrs (for a pool) or 2 hours for a spa to filter out finer particles. If the pressure gets too high, give the filter a quick backwash (1 minute with 1 minute rinse) or clean with the hose for the cartridge & D.E filters.

• Shock the pool with BioGuard Lite, or if you have a saltwater pool – BioGuard Salt Pool Sparkle to eliminate these wastes and any odours.

• If the water is cloudy, add the recommended shock dose of your sanitiser (chlorine for a pool, and bromine or Oxysheen for a spa) and run the filter for a few hours.

• Bring a water sample down to us at Poolside Beaconsfield for testing, and have it balanced up as soon as possible and ready for the next time!

We’re always here to help so if you need a pre-party cleanup and balance, or you’ve had your big party and need some professional help on the cleanup, click below to book online or call us directly on 03 9769 3252.