What Is A Pool Skimmer And How Does It Work? Learn How They Can Remove Debris from your Water’s Surface

Pool Skimmer

The skimmer is one of the most important components in your pool setup. Their sole purpose is to remove debris from your pool so that the water is clean and healthy for swimmers.

Skimmers are made to pull the top 1/8 inch of the pool water and their suction power is powerful but so subtle so most swimmers don’t even notice that skimmers are installed in the pool. But, if there were no skimmers around, the pool will get in such a horrible shape that everyone will notice.

The questions will follow: why is the water dirty? Why is the bottom of the pool dark and full of “stuff”? Why is my filter not working properly? Why has my pool pipe died on me?

How a pool skimmer works should not be asked when it’s too late, so let’s get to learning as much as we can about pool skimmers right now!

They are installed near or (as is the case with floating skimmers) on the surface of your pool to catch floating debris before it sinks to the bottom of your pool or, as we said, get sucked in and cause damage to your pump or filter.

Pool skimmer parts include skimmer baskets, a lid or door (also known as a weir flap), and a constantly open channel through which water flows.

Water enters a pool through a main drain, a skimmer, or both. It travels to a three-port valve and into the pump, which is run by a pump motor. From there, the water travels through a filter, then up to the heater (if installed) and back through the valves to the pool return lines.

swimming pool

​Image Source: pixabay.com

This is where the skimmer springs into action. Some pools have more than one skimmers with the main function is to pull water into the system with a skimming action. This means that a skimmer pulls in dirt, oil, leaves, twigs, and debris before they can fall to the bottom of the pool. In addition, the skimmer provides a conveniently located suction line for vacuuming.

Many pool circulating systems have at least two surface skimmers connected to the pump. While most skimmers are built into the pool, some models are designed to hang on the side. Most are molded, one-piece plastic units. Older pools most frequently have built-in-place concrete skimmers.

For the most efficient collection of debris and proper pool water circulation, there should be one skimmer for every 500 square feet of pool water surface.

How does a pool skimmer work?

Skimmers pull water into the skimmer which also forces debris in. There it gets collected by pool skimmer baskets. From here, it is the responsibility of the pool owner to empty the pool skimmer basket before debris blocks water from flowing through the pool skimmer. It’s as simple as that.

For inground pools, the skimming is performed by the weir, which regulates the amount of water entering the skimmer. Since the weird adjusts to permit only a thin layer of water to spill over, water is pulled off the surface quickly―keeping a large part of the pool surface clear.

While above ground and inground pool wall skimmers essentially serve the same function, they are installed in different ways. They are your pool’s first defense against dirty water and are extremely important for removing debris and maintaining the clarity of your water. This is way proper installation is very important.

Emptying the skimmer basket is also a part of regular routine. Additional use of baskets for putting the chlorine tablets in, rather than using chlorinators is questionable for the following reasons:


​Image Source: pixabay.com

  • ​You need to manually put chlorine tablets into your skimmer and do it frequently.
  • ​When the water is not circulating, the chlorine keeps dissolving. It leaks into your pool, through the skimmer door, and bleaches your liner if the water is left un-circulated for longer periods of time.
  • ​It allows chlorine to circulate through your pump and filter system, which can cause your system to get damaged by chlorine.
  • ​You clog up your skimmer basket with chlorine tablets, rather than leaving more room for debris.

The skimmer which is positioned in a good spot can keep about 500 square feet of water surface clean. If the debris gathered by the skimmer is left to accumulate, it can put additional strain on the pump. For this reason, among others, the skimmer basket should be cleaned out daily regularly and chlorine tablets do not help.

Another important point for optimal skimmer performance is that the skimmer must be installed with an equalizer line, which is a pipe that connects from the bottom of the skimmer basket through the pool wall and into the water.

The equalizer helps to prevent air from being sucked into the system if evaporation causes the water level to drop below the weir level. You need to make sure that air doesn’t enter the system because it could cause the pump to stall.

​The Skimmer and the Weir

Most skimmers consist of a tank with a projecting throat-like device on its upper side. There, a self-adjusting weir (or floating weir) performs the skimming action by regulating the amount of water that goes into the skimmer.


​Image Source: pixabay.com

Because it adjusts to allow only a thin sheet of water to spill over, velocity, not volume, is the key to good skimming action. It also needs to have an equalizer line which is a pipe that extends from the bottom of the skimmer about 12 to 18 inches through the pool wall and into the water. This, as we said, is important to prevent air from being sucked into the system when the water level gets low.

Skimmers work best when located on the “down wind” side of the pool because the wind helps push debris toward its opening. Water pours over a floating weir that allows debris to enter. When the pump is shut off and the suction stops, the weir floats into a vertical position, which prevents debris from floating back into the pool.

Some skimmers don’t have this type of weir and use a floating barrel as part of the skimmer basket. The basket collects leaves and larger pieces of debris, allowing you to remove them easily. 

Replacing a Weir


​Image Source: pixabay.com

Luckily, a weir is a fairly easy part to replace. With a pair of pliers, you simply need to remove the old or damaged weir from the skimmer and insert the replacement in the same position by pulling out its pins. A spring should release retaining rods that push against the skimmer walls.

​Overall importance of properly working skimmers and different types

What skimmers do is collect all debris, bugs, twigs, leaves and prevent the unwanted particles from sinking to the pool’s bottom and also from debris getting pulled into your pool system, damage the pump or clog your filter.

Pool skimmers are necessary for both above ground and inground pools to keep the water clean and maintain proper functioning of the filtering system.


​Image Source: pixabay.com

Swimming pool skimmers are a must have for both inground and above ground pools and should be purchased along with your new pool, maintained regularly and replaced (or replace damaged or worn parts only) if needed.

The key question is whether you’re looking for an above ground pool skimmer or an inground pool skimmer as they are quite different. 

​Inground pool skimmers

These are set into the concrete wall part in the water, part slightly above. They are stronger than above ground pool skimmers but also more difficult to replace as the parts are not that easy to access.

Because pool skimmer parts are often made of plastic, inground pool owners may notice that their pool skimmers sometimes spring leaks. Concrete is quite heavy and plastic pool skimmers cannot always put up with the pressure created by the heavy construction of inground pools. 

​Here’s a diagram with parts:

Skimmer With Equalizer

​Above-ground pool skimmers

Want to buy an above-ground pool? We reviewed 9 Intex above-ground pools for you!

While serving the same purpose and operating on the same principal, above-ground pool skimmers have a faceplate and they are installed in the wall of the pool by setting the faceplate on the inner portion of the pool and the pool skimmer on the outside of the pool.

This means the pool skimmer and the faceplate seal the pool wall and liner between them, using a faceplate gasket to prevent leaking.

Pool Skimmer

When purchasing an above ground pool skimmer, make sure it can be mounted on your pool.

​What’s new in the range of skimmers available on the market?

Modern developments in the pool industry have introduced inexpensive but practical manual pool skimmers as well as floating and robotic pool skimmers have entered the market and offer an alternative to a stationary model.

Manual are easy enough to use and will last a long time if you choose the quality materials.

Automatic skimmers, which operate on batteries or solar power, float on the surface of a pool, collecting debris as it moves through the pool. They significantly cut down on time and work necessary for pool maintenance, especially in areas with windy weather where winds carry leaves and debris right into your pool.

They also lower the cost of energy consumption, as they are designed to operate independently of the pool pump. Some automatic skimmers are designed to connect to an automatic vacuum pool cleaner which then collects surface debris as it floats through the pool. 

Laurie S.

As a multi home owner for 15 years I've tried out a ton of pool products and methods and have found out the best ones that work for me. I love helping out other people with real, honest advice and spending time with my family. If you have any questions please don't hesitate to contact me in the about or through a comment.

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