Skimmers are found in essentially every type of swimming pool whether it is gunite, vinyl-lined, fiber-glass or above ground. Depending on the size of your pool, you could have 1, 2, or even more skimmers installed. The skimmer in your pool is the thing that looks like a mini mouth in the side of your pool, near the top of the water. Bonus tip: You should keep your water level about halfway up the mouth of the skimmer. This helps it accomplish its primary goal… Which is to suck water out of the pool and through the filter system. Making your skimmer one of two suction lines within your pool’s circulation system. The other is the main drain that resides at the deepest point of your swimming pool to help circulate deeper water and catch debris that has sunk to the bottom. Pool skimmers come in many different sizes and vary in their plumbing however a few parts remain regardless of the make or model.