Pool Pump Systems

To most of us, a pool is, more or less, a big hole in the ground. We don't see most of the expensive machinery in a pool system, because it's usually tucked away in nearby pump room. But this is the stuff that really makes the pool work.

The heart of the pool system is the water pump. In a typical pump system, an electric motor spins an impeller inside the pump housing. The impeller drives the water from the various drains through the filter and back out to the water inlets.

Swimming pool pipes from the main drain, skimmer and vacuum ports
Pipes from the main drain, skimmer and vacuum ports lead to the pumping system.

Just before it flows into the pump, the water passes through a metal strainer basket that catches leaves and other large debris that might clog up the pump.

Swimming pool strainer basket
The strainer basket sits right in front of the pump.

Swimming pool strainer basket removed for cleaning
The strainer basket, removed for cleaning

Next, the water flows into the filter (or, in this setup, one of two filters). In the next section, you'll find out what happens at this point in the system.

Light it Up

These days, most swimming pools are built with underground lights, partially for aesthetic appeal but mainly to let night swimmers see what they're doing. In one common underwater lighting design, an incandescent light bulb is sealed in a water-tight fixture, which sits inside a niche embedded in the pool wall. The insulated electrical wire runs into the fixture through a special seal, keeping water away from the conductive elements. The wire runs back to the house (or wherever the power source is) through a long tube, which is filled with water most of the way. There is enough extra wire in the tube that you can pull the entire fixture out of the niche and up above the water level when you want to change the bulb.

Some people use fiber-optics to light their pools, instead of embedded incandescent fixtures. In this system, the actual light source doesn't have to be underwater, so you can skip the whole bulb-changing, water-proof electrical-component issue entirely.