These cleaners attach to one of the suction ports at the pool. Usually, this port is the skimmer, or your pool may have a separate vacuum port where the cleaner's hose can attach. With the hose attached and the filter pump running, suction is created on the underside of the cleaner. The cleaner moves randomly, or automatically around the pool with motion created by a device that gives a stop/ start pulsing of water. As the unit travels, debris is sucked up through the neck and then the hose, past the suction port, through the pipe, and stops at the filter pump strainer basket, while smaller debris passes through to the filter. Adjustments on the hose, the unit itself, and flow volume will create different cleaning patterns, so as to maximize pool coverage.

These cleaners attach to the pressure side (return) of your circulation system.  The water that is being pumped or "pushed" back to the pool powers these units which have their own hydraulic power plant inside. Being on the pressure side, these units have distinct advantages. They are helpful in distributing clean filtered water around the pool and having their own debris bag means that they don't compromise the filter system. Even with the bag full, a pressure cleaner still operates, stirring debris up;  it just won't suck up any more debris until the bag is emptied.

These are self contained electric cleaners which are put into the pool when there is a need for cleaning. A transformer is plugged into a wall outlet and a long cord from the unit plugs into the transformer receiving low voltage power to operate the cleaner. This power operates two motors; a pump motor which draws debris into the unit's filter, and a drive motor which moves the unit around the pool. The advantage of owning a robot cleaner include their self contained filter, which is easily cleaned. They also do quite well with their coverage. Some units are computer chip controlled and some even have remote controls so you can steer the unit from a lounge chair! Being that they are the only cleaners not attached in any way to the pool's circulation system, they produce no resistance or back pressure on the filtering. Their cost can be more than suction or pressure side cleaners.