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 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.
What Is a Pool Skimmer?
Pool skimmers are filters that capture floating debris before it can sink to the bottom of the pool.
Most skimmers on in-ground pools are built into its 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.
Skimmers for In-Ground Pools
A surface skimmer is typically made of plastic (PVC) or precast concrete, and it includes a tank with a projecting throat on its upper side. The skimming action is performed by the pool weir, 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.
One skimmer that is 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. In addition to maintaining your pump, cleaning the skimmer also allows your filter to work as efficiently as possible. For these reasons, the skimmer basket should be cleaned out daily during swim season.
A 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. This equalizer helps to prevent air from being sucked into the system if evaporation causes the water level to drop below the weir level. Make sure 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.
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 an automatic pool cleaner (vacuum), then collect surface debris as it floats through the pool. Debris is sent to the pool's filtration system.
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.
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.
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.