Brown spots on pool plaster are usually caused by either decaying organic matter (leaves/acorns releasing tannins) or oxidized metals (iron or copper) in the water or plaster mix.
To fix pool plaster discoloration, first identify if the stain is Organic or Metallic. Test an isolated stain by holding a chlorine tablet against it (if it fades, it is organic) or by pressing crushed Vitamin C/ascorbic acid on it (if it lightens, it is metallic).
Pool plaster typically lasts 55𝟓 to 1212𝟏𝟐 years, with an average lifespan of about 777 to 101010 years. Its longevity depends heavily on consistent water chemistry.
For extreme staining or serious algae blooms, plaster pools can be cleaned with an acid wash with muriatic acid, or the safer to use Acid Magic.
As the plaster dries out it will become patchy, a mixture of brown and pink. Once dry, the plaster will be pale pink in colour and all of the brown patches will have disappeared.
Brown stains in a fiberglass pool are usually caused by either metals (like iron or copper) or organic matter (such as decaying leaves, berries, or algae). To safely remove them without scratching the delicate gel coat, you must identify the type of stain and use targeted, gentle treatments.
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How To Get Rid of Organic Pool Stains: Generally, chlorine is the solution here. However, now that we know your 'standard' chlorine levels do not provide sufficient chlorine to combat the organic stains, you'll need to shock your pool.
Diluted Dawn dish detergent provides the gentle cleansing effect needed to loosen dirt without harming the pool cover fabric. Scrub one side, and then turn the pool cover over to scrub the other. Rinse both sides with plenty of water to remove the detergent and any remaining dirt.
Pool Resurfacing Costs: The Nitty-Gritty
Expect $6,000 to $15,000 for most pools, with $11,000 as a ballpark average. If you like to run the math, it's usually around $6.41 to $7.65 per square foot. For example, a 16-by-32-foot pool typically costs around $3,328 to resurface if you pick standard plaster.
How to Tell If Your Plaster Needs Replacing
Chlorine keeps your pool clean, but it can harm pool surfaces over time. High chlorine levels speed up damage to concrete, plaster, and even painted finishes. Harsh chemicals react with the surface, causing rough spots or fading color.
Mix 1/4 cup of white vinegar, 1 tbsp. of dish soap, and water in a spray bottle. Spray the area liberally and let soak for 5-10 minutes and then blot again with a clean, dry towel until stain is removed.
Two-Step Dry Polishing & Resurfacing Process
True brown algae has a yellow-brown color. It's a chlorine-resistant algae that clings to the walls of pools, and it's most common in shady areas. While brown algae is not as common as green pool algae, it's more stubborn. If not treated properly, it will quickly grow back.
Baking soda (sodium bicarbonate) acts as a natural buffer that raises both your pool's total alkalinity and its pH. It prevents severe pH fluctuations (known as "pH bounce"), clears cloudy water, prevents equipment corrosion, and helps your chlorine sanitize more effectively.
How to Remove Pool Stains Without Draining
Pool plaster typically lasts 55𝟓 to 1212𝟏𝟐 years, with an average lifespan of about 777 to 101010 years. Its longevity depends heavily on consistent water chemistry.
To fix pool plaster discoloration, first identify if the stain is Organic or Metallic. Test an isolated stain by holding a chlorine tablet against it (if it fades, it is organic) or by pressing crushed Vitamin C/ascorbic acid on it (if it lightens, it is metallic).
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The lifespan of plaster depends entirely on its application. Interior wall plaster can last 50 to 100 years, pool plaster lasts 5 to 15 years, and an unapplied bucket of pre-mixed plaster mud is viable for 1 to 5 years.
In some cases, if the plaster is severely damaged beyond repair, it may be necessary to remove the old plaster and start fresh. However, this is not often necessary. By following the proper steps to prepare the wall and applying the plaster correctly, plastering over old plaster can be a simple and successful process.