Pool Stain Removal Techniques

copper-stained-pool-being-acid-washedSpring pool openings can reveal all sorts of surprises, and one of the worst is discovering stains of all colors on your pool.

Stains run the gamut of small rust marks, to all-over pool color changes. Plaster pools tend to stain more easily than vinyl or fiberglass, but also can use more aggressive stain removal techniques.

How you approach stain removal will have a big effect on your success. This post is about some methods for removing pool stains, for vinyl and plaster pools.

Clean The Pool

clean-the-pool-firstThis step seems intuitive, but many people rush right into treating a pool stain, without removing organic debris that may be partly to blame for your pool stain.

Vacuum, brush (lots of brushing), and skim the pool while filtering to trap suspended particles. Backwash as necessary. The water should be as clean and clear as possible before jumping ahead to stain treatment.

Balance the Chemistry


This second step may be more important than the first, and in some cases, you may open the pool to stains, but after cleaning, filtering and balancing the pool water chemistry, they have faded away.

water-balance-parametersTest and balance (with a 5-way test kit or test strip), all of the parameters of water balance – pH and Alkalinity, Calcium Hardness and cyanuric acid, aka conditioner or stabilizer. For safety, accuracy and efficacy, only open and add one pool chemical at a time, and be sure to test the pool again after 8 hours, to see if additional balancers are needed.

Swimming Pool Stain Treatments

For most pools, the first treatment to try after balancing the pool water is to use pool shock, which can remove algae stains, organic stains from leaves or worms, and will usually bleach an all-over pool stain a few shades lighter.

For a vinyl pool, you shouldn’t use super high doses of pool shock for pool stains, and you can’t drain it and acid wash or pressure wash the pool. Here’s some safe and effective ways to remove stains in vinyl or plaster pools.

A+ Stain Remover

aplus-stain-removalA+ Stain Remover is safe for all pool types, and easy to use. A combination of powerful stain fighting ingredients that synergizes when you add your favorite pool shock.

Great treatment for step stains and isolated pool stains. For all-over stain removal, use 1 bottle per 10000 gals.

Vinyl Liner Blue Stuff

jacks-magic-vinyl-liner-blue-stuffThe Blue Stuff by Jack’s Magic, is made to control and prevent mineral staining in vinyl lined pools, and can also be used to remove metal stains on vinyl or plaster.

When stains don’t respond to chlorine treatment and vigorous brushing, you may have metal stains from copper, silver, or iron or mineral stains from calcium scale mixing with dirt.

EZ Stain Remover

ez-stain-removerEZ Stain Remover is a mixture of sodium sulfate and sulsamic acid and is one of our most powerful stain fighting formulas.

Adjust your pH to 7.0, and allow chlorine level to drop below 0.5ppm, and then broadcast the EZ stain remover granules over the pool stain. 1 bottle per 15,000 gals for all-over stains.

Stain Free

stain-free-bwStain Free is 100% Ascorbic Acid – vitamin C! Just pour it in the pool, and organic stains instantly disappear. To test at home first, grind up several Vitamin C tablets, and sprinkle over your pool stain.

Use 1 lb per 10000 gals. For mineral or metal staining, follow up with treatment of Metal Free, to lock them tightly in solution.

Swimming Pool Stain Prevention

To keep stains from coming back, keep a clean pool with balanced water, and try these methods below for dealing with difficult mineral and metal problems.

Eclipse3 Ejector

eclipse3-ejector-bwEjector traps minerals and metals in your pool filter, and ejects them upon backwash or cartridge cleaning.

After removing stains from your pool surface, prevent future stains by trapping suspended minerals and metals, and removing all traces from your pool filter – with Eclipse3 Ejector.

CuLator 4.0 PowerPak

culator-4-powerpakCuLator 4.0 has 4x the power of the original metals absorption pouch, the 4.0 PowerPak sucks metals from the water, to prevent stains from copper, iron, manganese, cobalt and other metals.

Just drop one PowerPak into your pump basket, instead of sequestering metals, it actually removes them from the pool.

Metal Free

Metal-free-bwMetal Free, from Natural Chemistry is made from citric acid products. Unlike other metal sequestrants, this strong chelator contains no phosphates, and won’t damage the soil around the pool or backwash area.

Improves water clarity, prevents stains and discoloration of pools and steps. Use 1L bottle per 20000 gals of pool water.

~ If you’re battling pool stains this season, remember to clean and balance the pool first, then visit our Pool Stain Solutions section for powerful pool stain removers, for stains of all colors!

Davy Merino
InTheSwim Blog Editor



Pool Stain Removal Techniques — 2 Comments

  1. We leave in Eastern Canada and our pool is covered in snow during the winter. We are wondering if we should treat stains this fall when we close the pool or next spring when we open it.

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