Brown stains on the bottom of a pool are typically caused by metals in the water (like iron or manganese) or organic debris. They can also indicate yellow/mustard algae or the settling of fine, dead algae after a pool shock.
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.
To remove brown stains from a pool bottom, first identify if they are metal (iron) or organic (leaves/algae). Metal stains require ascorbic acid or a stain remover like Robelle Mineral Out, while organic stains respond to shock. For severe stains, use Jack's Magic Copper & Scale Stuff to lift stains without draining the pool.
The causes of brown stains in the swimming pool
The first possible cause is that the concentration of iron is too high. This iron concentration needs to be under 0.2 mg/L, otherwise iron oxides build up due to air oxidation. A second possibility is the presence of brown algae.
How to Remove Brown Algae from Your Pool?
The quickest way to remove brown algae (diatoms) in an aquarium is through aggressive physical removal followed by water changes and silicate reduction. It is a common occurrence in new tanks.
Alternatives to Chlorine In Pools You Could Consider
While you technically can swim in a pool with algae, professionals strongly recommend against it. Algae itself isn't toxic, but its presence means your sanitizer levels are depleted. This allows harmful bacteria (like E. coli) to thrive, and the algae itself makes surfaces dangerously slippery.
Adding vinegar (acetic acid) to a pool temporarily lowers the water's pH and helps dissolve calcium buildup. However, it is a weak acid. Because you need massive quantities to adjust pool chemistry, it introduces organic sugars that can feed bacteria and algae.
Once the algae is killed, some of it will be captured in the filter, but because the dead algae particles are so fine, they will settle to the bottom of the pool, usually appearing as a gray or brown dust.
Swimming pool stains are most often caused by: Metals or minerals in pool water coming out of solution. Rust emerging through the wall, floor, or around fittings. Organic material like leaves, dirt, oils, worms, or algae.
Getting dead algae off the bottom of your pool without a vacuum requires a combination of chemical breakdown, physical circulation, and gravity. You will kill the algae, clump it together, stir it into the filter system, or manually siphon it out.
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.
Brown stains in a swimming pool are usually caused by metal (iron or copper) or organic debris (leaves, acorns, and algae). To treat them effectively without draining your pool, you will need either an Ascorbic Acid-based stain remover (for metal stains) or a heavy chlorine shock (for organic stains).
Dawn dish soap itself does not chemically kill algae. However, it acts as an excellent surfactant. It breaks the surface tension of water and lifts algae off surfaces, making it highly effective when used alongside mechanical scrubbing or as an additive in DIY exterior cleaning solutions.
Swimming in a pool with excess chlorine (typically above 4 ppm) can cause immediate physical distress. Common symptoms include red, itchy, or burning eyes, dry and irritated skin, brittle hair, and respiratory issues like coughing, wheezing, or a sore throat.
Yes, you can absolutely mix Dawn and vinegar. It creates a highly effective, inexpensive DIY cleaning solution favored for cutting through soap scum, hard water stains, and grease.
What you may not know is that hydrogen peroxide is a powerful oxidizer that can be combined with ultraviolet light to disinfect swimming pools. The combination of ultraviolet disinfection with hydrogen peroxide allows pool owners to safely eliminate all chlorine in their pool or spa.
The 3 C's of Pool Maintenance. The 3 C's of pool maintenance are circulation, cleaning and chemistry.
To kill algae on the bottom of your pool, you must shock the pool with a high dose of granular or liquid chlorine and actively brush the settled algae into the water. Algaecides do not kill established algae; they only act as preventatives.
When you spot algae starting to grow, treat it immediately before it turns into a full bloom. Scrub the affected walls and surfaces with a stiff brush, clean or backwash your pool filter, and shock the pool heavily with liquid chlorine while keeping your pump running continuously.
Our pool experts at Parnell Pool and Spa never recommend swimming in algae pool water because of the harmful bacteria that feed on the algae.
Getting rid of pool algae without chemical algaecides requires heavy mechanical labor and physical filtration. You can do this by thoroughly brushing all pool surfaces to dislodge the algae, vacuuming the pool directly to waste, cleaning your filter, and running your pump for 24-48 hours until the water clears.
A cowboy pool (also known as a stock tank pool) is a large, galvanized metal livestock watering tank that has been repurposed into an above-ground swimming or soaking pool. They offer an affordable, stylish, and low-maintenance alternative to traditional in-ground pools.
Because bleach is weaker than pool-grade chlorine, you'll need to use more of it. As a rule of thumb: 1 gallon of 6% bleach will add about 5 ppm of free chlorine to 10,000 gallons of pool water. Use a pool chemical calculator to determine the exact dose based on your pool volume and current chlorine level.