A skimmer is a basic filtration system that removes larger objects, such as leaves, debris, and dead insects, from the swimming pool. It has a small or medium-sized opening on the side of the pool, located just under the water surface. The internal mechanism sucks in water, along with floating debris and dirt. After being filtered and cleaned, the water will be pumped back into the pool. Other than a regular built-in skimmer, there’s also an above-ground skimmer that floats and hangs on plastic arms. This type of skimmer catches floating debris that you can collect manually with a hand skimmer. For extra convenience, you may consider getting a robotic skimmer that swims around and collects debris from your pool. A robotic skimmer can be battery or solar-powered and programmed to clean up your pool at certain times of the day. It’s very important to thoroughly clean up your swimming pool of any floating debris, before using any kind of chemical-based cleaning product, such as chlorine or algaecide. Decaying objects like leaves and dead insects will continue to release organic substances into the water. If there’s no skimmer, dry leaves may decompose and form organic sediment on your pool’s floor, making it a perfect habitat for algae and harmful microorganisms.