Why Does Our Inground Pool Make Huge Air Bubbles on Start Up?

Bubbling Trouble

• A swimming pool is not a Jacuzzi; therefore, bubbles in the water are not a natural occurrence. Unless the swimming pool filtration system includes an “ozonator,” the presence of bubbles at the opening of a pool’s water return is a sign of trouble. Air is entering the filtration system somewhere along the line.

Low Water

• If the water level in the pool is low through evaporation, splashing or a liner leak, small amounts of air can be pulled in at the skimmer throughout the day. Then, as the pump sits overnight, the air collects in the system, forming larger pockets, which show as bubbles when the pump starts.

Valves

• If your filter has a valve on top that allows you to change various settings, the valve may be worn or the gasket could be compromised, allowing air to be pulled in around the edges. The valve or gasket can be damaged if the valve is turned while the pump is running or is turned the opposite direction than normal.

Gaskets and O-rings

• Your pool's pump and filter might have bad gaskets or O-rings. As the rubber in gaskets or O-rings dries out, it shrinks and pulls away from the fittings, allowing small amounts of air to pass by. If you see any places on or around your pump or filter where water is leaking, it's likely this is where the air is entering. Even small amounts can indicate ill-fitting plumbing.

  All gaskets and O-rings need to be lubricated at the beginning and end of the swimming season. When doing so, do not use petroleum jelly. The oils in the jelly break down the rubber. Instead, use a silicone- or Teflon-based lubricant.

Pump Lid

• Because it causes large amounts of suction, your pump's pool lid must be tight. If it is loose or the main lid gasket is dried out, air will be pulled in anytime the pump is in use. Also, pieces of debris under the gasket or in the threads of the lid can allow air to be drawn into the system.

Pipes and Fittings

• As the pool season progresses, natural earth vibrations can cause the pool's threaded plumbing fittings to slightly back turn, or glued fittings can dry out over time, allowing air pockets to form in the pipes.

  The skimmer pipes, themselves, also might be compromised. This is the spot where you don’t want to find the problem because often it means bringing in a backhoe to dig up buried lines. Pipes that have been in the ground for a long time might be cracked due to settling, age or tree roots. A tiny crack allows air seepage over time causing bubbles. Broken skimmer lines often happen during the winter because water was left in the pipes and froze.