Why Does My Skimmer Have Two Holes?

If you own a swimming pool or have seen a skimmer in action, you might have noticed that skimmers usually have two holes. This design may seem puzzling at first, but there’s a logical reason for it. In this article, we will explore the purpose of the two holes in skimmers and why this design is crucial for maintaining a clean and well-functioning pool.

The Main Drain and Skimmer Operation

To understand why skimmers have two holes, it’s important to grasp the basic operation of a pool’s filtration system. The skimmer is a vital component of this system, responsible for removing debris and contaminants from the surface of the water. It works in conjunction with the main drain, which is usually located at the bottom of the pool.

When the pool pump is running, water is drawn into the skimmer and through its basket. The skimmer basket acts as a filter, capturing leaves, bugs, and other floating debris before they sink to the bottom. The water then flows from the skimmer to the pump, which pushes it through the pool filter and back into the pool.

Skimmer Holes: Equalizing Water Pressure

The two holes in a skimmer serve a vital purpose in maintaining the efficiency and functionality of the skimming process. These holes are strategically placed to equalize the water pressure inside the skimmer, preventing it from becoming overwhelmed or causing any suction issues.

1. Skimmer Throat

The upper hole in the skimmer, known as the throat or weir, is where the surface debris enters. It is equipped with a floating door or hinged flap, known as the skimmer weir, which rises and falls with the water level. The purpose of the skimmer weir is to create a constant opening that allows debris to flow into the skimmer while minimizing the escape of collected debris back into the pool.

2. Skimmer Bottom

The lower hole in the skimmer, usually positioned at the base of the skimmer body, is known as the skimmer bottom. This hole helps regulate the water flow and prevent airlock within the skimmer. The skimmer bottom typically connects directly to the main drain, allowing water to flow through the skimmer and main drain simultaneously.

Table: Comparison of Skimmer Holes

Skimmer ThroatAllows surface debris to enter and prevents its escape back into the pool.
Skimmer BottomRegulates water flow, prevents airlock, and connects to the main drain.

Ensuring Optimal Pool Filtration

By having two holes, skimmers create a balanced water flow and maintain an optimal filtration system. Here are a few key benefits of skimmers with two holes:

  • Efficient Debris Removal: The skimmer’s dual-hole design enables effective removal of debris from the pool’s surface, ensuring cleaner water.
  • Preventing Clogs: The skimmer throat captures larger debris, reducing the chances of clogs in the pool pump or filter.
  • Water Circulation: Proper water flow from both the skimmer and main drain helps evenly circulate the water throughout the pool, enhancing overall filtration.
  • Preventing Airlock: The lower skimmer hole, connected to the main drain, prevents airlock issues by allowing water to flow continuously.

In Conclusion

So, the next time you wonder why your skimmer has two holes, remember that each hole serves a specific purpose in maintaining your pool’s cleanliness and functionality. The upper skimmer throat ensures debris can enter while minimizing their escape back into the pool, and the lower skimmer bottom regulates water flow and prevents airlock. Together, they contribute to an efficient pool filtration system, keeping your swimming pool sparkling clean and inviting.