Activities Sports & Athletics What Is the Proper Water Level in My Swim Pool? Share PINTEREST Email Print Frank Rothe/Photodisc/Getty Images Sports & Athletics Swimming & Diving Technique Gear Workouts Health & Safety Diving Baseball Basketball Bicycling Billiards Bodybuilding Bowling Boxing Car Racing Cheerleading Cricket Extreme Sports Football Golf Gymnastics Ice Hockey Martial Arts Professional Wrestling Skateboarding Skating Paintball Soccer Table Tennis Tennis Track & Field Volleyball Other Activities Learn More By Woody McDowell is a pool service professional. our editorial process Woody McDowell Updated April 23, 2018 Although it's often overlooked, maintaining the right water level in your swimming pool is essential the proper operation of the pool filter system. The perfect level is for the water level to be at the halfway point on the skimmer hatch along the side of the pool. It's acceptable for the water to fall anywhere from the one-third to one-half way mark, but if the water level is below or above this range, you should add or remove water to return the water level to an optimal range. Problems Caused by Improper Water Level The pool skimmer is the entry point for your pool's filtration system, and if the water level is too low or too high, the water cannot flow properly into the system's pipes and filter equipment. Under normal operation, the pool water enters the filtration system through the skimmer, where it is transported through pipes or hoses into the filter and then returns back into the pool via the return jets. The skimmer also is responsible for trapping large pieces of debris, which are strained out by the skimmer's basket. If the water level is too low, no water at all flows into the skimmer and on through the filter system. Not only will there be no filtration occurring, but the filter equipment and pump motor may be damaged if it runs with no water flowing through it. If the water level is too high, on the other hand, the water flow through the pump system will not be as efficient. The idea water level is at the exact halfway point on the skimmer door, and when the level gets below the one-third point, more water should be added. Adding or Removing Water Rarely, it may be necessary to remove water from a pool to lower the water to an optimal level. Heavy rains, for example, may temporarily elevate the water level in our pool and require that you remove some water. When this occurs, it's usually easy enough lower the water level, either by bailing or by using the DRAIN setting on your multiport valve while running the pump. Often, though, a day or two allowing the pool to sit in the sun will cause the water level to return to optimal levels through evaporation. Until the water returns to a good level, avoid running the filter system. Much more commonly, the water level drops to an unsafe level due to evaporation or heavy use by swimmers. Check your water level daily, and add water whenever the level approaches the one-third mark on the skimmer door. If the water level is below the skimmer hatch, don't run the filter system at all until you've added water. This will prevent expensive damage to your pool filter.