How To Remove Stains From a Pool

It is the dread of any pool owner: seeing spots appear on the coating of a pool. Often difficult to remove they quickly become a nightmare. All stains are not cleaned in the same way, for the simple reason that they do not all have the same origin. The treatment will also depend on the coating of your pool: liner, coating, or fiberglass. Here is our guide for how to remove stains from a pool.

How To Remove Stains From a Pool Liner

Brown spots. Removing brown spots on the liner of your pool can be a relatively easy operation if they result from the presence of organic waste or are a sign of deposits of dead algae. On the other hand, it promises to be more delicate if it is a question of micro-mushrooms which, in reality, have developed behind the liner, on the concrete part of your swimming pool, and appeared by the effect of porosity. It is generally the consequence of humidity that settled between the coating and the concrete.

How do you know if it’s algae or fungi?

If the spots reappear quickly after rubbing them, it is fungi. In this case, do the following:
Lower the pH to 6.8 and stop the filtration. Thus, the pores of the liner will dilate and the treatment will be more effective. Then, if you have only a few isolated sections, bring gloves, a chlorine tablet, and diving goggles and then rub in small circular movements, without pressing too hard, on the stain.

On the other hand, if the spots are almost everywhere in the pool, pour with a watering can sodium hypochlorite or, failing this, bleach as close as possible to the spots.
Finally, raise the pH to 7 or 7.2 and then filter the pool water continuously for 72 h before washing the filter.

If the waterline has turned yellow. This is due to the presence of floating fatty substances on the surface of the water. Even with regular maintenance of your pool, sunscreens, are formidable. To prevent the appearance of this famous yellow line, think of rubbing the edge with a suitable product, once a week.

To prevent the appearance of limescale, which promotes the adhesion of fatty substances, by also using an acid cleaning product. If, on the other hand, the water line is crusted, do as follows:
Fill the pool so that the water largely covers the yellow line.

Do shock chlorination. Set the pH to 7. Pour a metal inhibitor into the skimmer at the doses indicated (generally 40 ml for 50 m3 of water). On the 4th day, pour a new dose of product. On the 7th day, backwash the filter. Leave the filtration continuously on for the duration of the treatment.

Rust stains. They reflect the presence of metals in water (iron, copper, manganese). To remedy this, apply the specific products using a sponge after putting on gloves. You can also try white vinegar. To do this, attach a sponge to the end of a hollow tube and pour the liquid into it. Then rub on the stains.

Pink or Red spots. Viscous in appearance, they first appear on plastic surfaces (water toys, ladders, etc.). To make them disappear, lower the pH to 7 and scrub the stains with a sponge. Then do a shock treatment or use an algaecide.

For optimal efficiency, also leave contaminated objects in the water during the operation. The filtration system must also work continuously. Then 24 hours later, raise the pH to 7.2 and 7.6 and leave the filtration system on for another 72 hours. Wash the filter every day before the treatment. You can remove stains on a liner by using a specific cleaner sold in specialized stores.

You will apply it using a sponge or a glove, and scrub in circular movements. You can also use silver stone, which is a natural clay-based solution, or white vinegar.

How To Remove Stains From A Fiberglass Pool

Red, Black, Brown, Blue/Green spots. This may be due to the decomposition of organic matter (leaves, insects, etc.) or an excessive supply of metal ions.

What to do? The treatment of these stains on your fiberglass pool will take place over a week. On the first day, Acidify the pool by reducing the pH to 6, then carry out shock chlorination. Then add a ferrous ion product using the correct dosage. On the 4th day, add another dose of the same product. On the 7th day, backwash the filter. In the end, check that the pH has risen between 7.2 and 7.6 and then stabilize it. For prevention, be sure to keep the pH between 7.2 and 7.6.

Brown or Green spots. Have algae formed on the bottom and walls of your pool? To be sure, just see if they disappear on contact with a chlorine tablet. If this is the case, treatment is necessary. Practice shock chlorination then adjust the pH of the water to between 7.2 and 7.6 as well as the hardness. Run the filtration system all the time.

Then, do a flocculation treatment to increase the fineness of filtration and eliminate the algae in suspension. Allow a day to pass then brush the walls, wait for the residue to form at the bottom of the pool, and vacuum them directly to waste. Return the filtration system to normal operation.
To prevent algae from returning, it is advisable to use a pool cover which will thus block the photosynthesis process.

Brown or Black spots. They are undoubtedly fungi, which have formed due to insufficient filtration, or random cleaning of the pool. To remedy this, you will need to lower the pH to 6 in order to acidify the water, before initiating shock chlorination.
Note that to avoid the appearance of fungi, the pH should be kept around 6.8 and the chlorine level should be at least 1.5 mg / l.

White or Grayish spots. If they are rougher to the touch, it is tartar. Here is the solution. Acidify the pool water by reducing the pH to 6 and then, allow the pH to rise alone between 7.2 and 7.6. If it has not gone back far enough beyond the 7th day, use a product. If this was not enough to remove the stains, you will have no choice but to empty the pool to descale it.

Warning! Before emptying the pool, it is imperative to check that there is no water under the bottom, otherwise, it could rise and irreversibly damage your installation.


If you do not want limestone to return to the walls and bottom of your pool, you must regularly analyze the pH of the water and adjust it if necessary, between 7.2 and 7.6. In addition, it is essential to treat the water regularly (at least 3 times a year) with a suitable anti-lime.

Discoloration spots. This is no doubt due to repetitive shock treatment. The chlorine damages the Gelcoat coating of your fiberglass pool. Unfortunately there is nothing to do, except to empty the pool and redo the coating.


The water line turns fluorescent yellow. It is the sign of the presence of benzotriazoles or debenzotriazines present in sunscreens. Here are the steps to follow. Raise the water level to above the yellow line then adjust the pH between 7.2 and 7.6. Once it is done, carry out shock chlorination and add a metal-capturing product in the correct dosage.

In addition, if you do not clean the water line quickly after the first signs appear, then the coloring could become permanent.

Brown marks at the waterline. Fats, in addition to remaining on the surface, trap dirt. To overcome it, the water line must be cleaned regularly with a suitable product whose role is to prevent stains from becoming permanent. If the waterline resists this cleaning, lower the water level below the coloring and clean with a descaler.

How To Remove Stains From A Concrete Or Plaster Pool

Heavy metal is a pool’s enemy. I’m talking about the invisible metals dissolved in your pool water from sources like rain run-off, pool equipment, saltwater pool systems, or even your concrete pool deck surface. Bits of metal like screws or hairpins can make a nasty rust stain.

It’s important to know what kinds of metals are creating the stains in your pool. Here’s a pool stain chart as a guide for metal stain identification in pools.

Metals are certainly not the only cause of stains in a plaster-surfaced swimming pool. Leaves, berries, bugs, suntan oil, or even your water-loving dog can all contribute to staining. For plaster pool stains is to always start with the brushing and shock before going in with a bunch of trial and error stain removers.

These types of stains can be cleaned with good old fashion elbow grease using a combination of a PoolStone and pool shock. Pouring a bit of pool shock directly onto a stain works similar to bleach and is ideal for plaster surfaces.

Sequestering agents, commonly called Stain & Scale chemicals, can help keep minerals and metals in solution, locked up tightly at the molecular level, so they won’t precipitate, mix with other particles, and then attach to your pool surfaces.

Other Types Of Stains: These can include pool stains from mineral scale-like calcium and metals like copper, iron, or manganese. Minerals can come out of solution in hard water, and metals can enter from fill water that is high in metals, or from copper pipes or a pool heater exchanger – when water balance is not correct.

Removing Stains from a Plaster Pool

Granular pool shock or EZ Stain Remover for organic stains
Sequestering agents or A+ Stain Remover for metal stains
Stain Eraser or PoolStone for mineral stains
Enzymes for oily, dirty stains
Acid Washing for all plaster, tile and coping stains
Keep pool water balanced and brush often

Once again, having the correct water balance is important. Poor water balance can become corrosive or scaling, and both conditions can cause plaster pool stains by making it easy for minerals and metals to come out of solution.

How To Manually Vacuum Your Pool

The manual pool vacuum is an essential cleaning accessory and sufficient for cleaning small and medium-sized pools.

Given its low cost and ease of use, it is also a significant part of routine maintenance, especially in the event of a failure of your automatic pool cleaner, if you have one.

Why use a manual pool vacuum?

In general, a pool vacuum cleaner, whether manual or automatic, is an essential tool for removing dirt and debris that settles in the corners and the bottom of the pool.

Where the brush takes off the dirt, the manual vacuum cleaner will also suck them up through the filtration system or directly to waste. It protects against the deterioration of swimming conditions, water clarity, and helps keep a swimming pool clean, healthy, and pleasant.

The advantages of vacuuming a pool manually

Brushing the walls and floor of the pool prevents the formation of algae.
Brushing also targets areas in the pool where dirt tends to settle.

When should you manually vacuum the pool?

During the season, when too much dirt from the use of the pool or deposits have formed in the pool because of wind and bad weather. This involves removing the dirt and deposits from the pool to help the filtration system.

After a period when regular maintenance of the pool and water treatment could not be carried out. For example, after a return to service of the filtration system at the end of winter, or after returning from vacation, or because the weather has forced you to do so (green water with algae blooms, large volumes of debris to be removed from the water).

Note that if the debris to be removed is a lot (leaves for example), it is preferable to first use the net beforehand so as not to unnecessarily clog the baskets of the skimmers and the prefilter of the filtration pump.

How to connect a manual pool vacuum?

Connect the head of the brush with the telescopic sleeve and put the connection hose in the pool. It will be necessary to get the air out of the hose, starting by connecting it to the head of the brush. If air is sucked in, the pump won’t prime.

Immerse the hose and the brush in the pool water, holding the brush handle and the other end of the hose. Remove the air in the connection pipe by placing it in front of an outlet water jet or by immersing it vertically in the pool so that the air escapes from the pipe.

Now bring the pipe filled with water to the inlet connection point, you can put your hand on the top of the pipe so that the water does not escape if that part of the pipe is out of the water.

If the pool is fitted with a brush socket, then fit the other end of the hose into the brush socket.

If the manual vacuum cleaner must be connected to the skimmer, then fit the other end of the hose onto the skimmer. In this case, and depending on the model, it could be connected either directly to the pipe under the skimmer basket or if you have a disc that fits on top of the skimmer basket called a skim vac. The suction fitting will be on the top of the disc.

Should the pool pump be on or off when fitting the vacuum brush?

If the pump is stopped and you are alone, the connection hose can disconnect itself from the brush or the skimmer and partially re-fill with air.

In this case, it may be better to have two people (one holding the hose, and one which starts the pump) or, if you are alone, to correctly position the multi-way valve and the T and D valves. Turn on the pool pump before connecting the brush.

The multi-way valve must be in the filter position if there is not much dirt to vacuum. If the bottom of the pool is very dirty, it may be preferable to put the multi-way valve on the backwash (drain) position so as not to clog the filter.

If the brush is connected to the skimmer, open the valve of the corresponding skimmer and close the bottom drain valve. This will give more suction power to the brush.

How to use a manual pool vacuum?

Not many people like to vacuum a pool. Therefore we vacuum to fast which is a mistake.

Do not hurry and be gentle when handling the brush.
Gently vacuum all areas to be cleaned. By going too fast, dust and deposits will move up and resuspend in the water. The water will become cloudy and you will not see the bottom of the pool nor where you are vacuuming. Then you will have to wait for the dirt to settle down again.

The head of the vacuum cleaner must be effective on all surfaces and please respect the pool coating: walls, bottom, corners of the pool. If the coating is a liner, use a brush head that does not pierce the coating at the corners and edges. If the coating is a shell or concrete, a brush head with rollers is recommended so as not to scratch the coating.

Here again, the fact of going slowly makes it possible to avoid scratching, piercing or making impact points when the head of the vacuum cleaner bangs on the covering.

Once the vacuuming is finished, it is, of course, necessary to dismantle the brush and the hose.

Switching the pump off necessary to be able to empty the basket of the pump pre-filter and return the multi-way valve to the “Filter” position if it was on “Drain”.

Empty and clean the skimmer and pump pre-filter baskets. Return the T-valves to their original position and, if necessary, restart the pool pump.

To conclude

As the name suggests, a manual pool vacuum involves cleaning work that is done manually. We must remember to not vacuum to fast due to the risk of sucking air and putting most of the dirt back into the water.

It is possible to take turns vacuuming, doing it as a team, or make it in the form of a game.

That said, there is nothing more effective than vacuuming the dirt from a pool than with a manual vacuum cleaner. You can do without a robot but you can never do without a manual vacuum brush. And even if its easier to call a company for the cleaning and maintenance of your pool, you should always have one on hand.