What Does a Pool Skimmer Do?

Why You Need One for Your Swimming Pool or Spa

Swimming Pool Skimmer
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Think of a pool skimmer in a residential swimming pool like you would a gutter in a larger public pool: It helps to clean by skimming the water and capturing floating debris such as leaves, flower petals, dirt, twigs, dead insects, and oil (sunblock) while it's still on the surface of the water. Pool skimmers are filters that capture floating debris before it can sink to the bottom of the pool.

At their simplest, you can get a hand-held pool skimmer net and call it a day—but you would need to do that every day and several times a day. Skimmer boxes, floating skimmers, and robotic skimmers make this chore much more manageable.

Most skimmers on in-ground pools are built into their upper sides where the suction draws debris and traps it. These skimmers for pools are accessed via the pool deck area through a trap door or hatch. The skimmer is also typically in a convenient location to attach a suction line for a pool vacuum.

Types of Pool Skimmers

Skimmers for In-Ground Pools

A surface skimmer is typically made of plastic (PVC) or precast concrete, including a tank with a projecting throat on its upper side. The pool weir performs the skimming action, which regulates the amount of water entering the skimmer. Since the weir 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 water surface clear in pools with skimmers.

In addition to maintaining your pump, cleaning the skimmer allows your filter to work as efficiently as possible. One skimmer positioned in a good location can keep about 500 square feet of its surface clean. If the debris gathered by the skimmer is left to accumulate, it can put additional strain on the pump. For these reasons, the skimmer basket should be cleaned out daily during swim season.

A skimmer must be installed with an equalizer line, a pipe connecting from the bottom of the skimmer basket through the pool wall and into the water. This equalizer helps to prevent air from being sucked into the system if evaporation causes the water level to drop below the weir level. Ensure air doesn't enter the system―it could cause the pump to stall.

Many pool skimmers come equipped with automatic water level controls and automatic chlorinators.

Above-Ground Pool Skimmers

Because above-ground pools have thin walls, floating pool skimmers are most often used, but other options include units that hang on the pool's edge. To keep skimmers for above- and in-ground pools working properly, try to clean out the skimmer basket daily during swim season.

Robotic Pool Skimmers

In recent years, floating and robotic pool skimmers have entered the market and offer an alternative to a stationary model. Operated by batteries or solar power, these automatic skimmers float on the surface of a pool, collecting debris as it moves through the water. Devotees of products such as the Solar Breeze NX claim it cuts down on time and work, especially in areas prone to winds carrying leaves and debris into the pool or regions with lots of insects. It can also lower the cost of energy bills, as it is designed to work independently of the pool pump.

Other automatic skimmers, such as the whirlpool-like SkimmerMotion, are designed to connect to a robotic pool cleaner (vacuum), then collect surface debris as it floats through the pool. Debris is sent to the pool's filtration system.

Solar Pool Skimmers

Most solar pool skimmers are automatic or robotic models. Solar pool skimmers allow you to keep your swimming pool clean while using free renewable electricity from the sun instead of power docking them or using battery power. Many models will enable you to program them and put your pool skimming on a schedule without worrying about them.

Skimmers for Spas and Hot Tubs

Skimmers for redwood hot tubs usually have no basket; instead, they skim the surface and pull debris to a plastic screen. Some portable spas have skimmers with built-in cartridge filters. Hard-sided hot tubs and spas have built-in skimmers that continuously clear the water's surface, which provides a cleaner water quality overall than manual skimming net options for portable and inflatable hot tubs.

Pool Skimmer Prices

The price for a skimmer can range from $10 for a no-nonsense handheld skimmer net or more than $1,000 for a fully programmable "smart" robot skimmer that runs via wifi and an app, including numerous cleaning cycles and auto sensors.

Since pools need many accessories, including incidental costs like lighting, heating, and regular maintenance, people pay, on average, about $100 for a skimmer, according to HomeAdvisor.

What Size Pool Skimmer Do I Need?

The Pool and Hot Tub Alliance and the Association of Pool and Spa Professionals agree that there should be a minimum of one skimmer per 400 sq. ft. of pool surface area.

Should You Add Chlorine Tabs to a Pool Skimmer?

While some pool owners claim that placing their chlorine tablets―known as hockey or chlorine pucks―right in the skimmer basket cuts down on time, many pros advise against this. The high concentration of acid can break down parts of the filter, possibly causing a need for more frequent replacement. Instead, opt for a separate dispenser called a chlorinator or use a floating chlorine dispenser that distributes chlorine as it floats throughout the pool.

  • Where should my water level be on my skimmer?

    The water level should be halfway up the skimmer opening.

  • What is a good speed for a pool skimmer?

    Flow rates for pool skimmers are measured in gallons per minute. According to the National Sanitation Foundation, a minimum of 15 gpm is required for pool skimmers to function properly. The highest is about 75 gpm, with the most skimmers in the 25- to 55-gallon range.

  • Do you really need a skimmer in a pool?

    If you have a pool, you need a skimmer to remove debris from the pool's surface. Leaves and other debris will clog and overwork a pump, and you will have difficulty keeping a pool clean without a skimmer.

  • What is the disadvantage of a skimmer pool?

    The most significant disadvantage of a skimmer pool is that it can take a while to get clean. Many skimmers are passive with the water coming to them, or they are single units that float or roam, potentially not covering every spot of the pool.