In addition to keeping the chemical balance of the pool within proper parameters, the pool needs to be kept physically clean. The majority of this task is accomplished by a filter mechanism, which, coupled with a vacuum, will rid the pool of most foreign matter. Large debris will still need to be manually removed with a net. While the pump, vacuum and filter will remove most detritus from the pool, this matter must still be dealt with periodically.
The strainer basket on the pump serves as a preliminary filter for large debris so that the actual filter is not clogged. It resembles a sieve and should be cleaned out whenever it is full, especially after a storm. Turn the pump off, set the valves from the strainer basket to the pool to “closed” and remove the sealed lid from the basket chamber. Inside the chamber is the strainer basket. Remove it, clean the leaves and pebbles out and replace it. Make sure the gasket on the chamber lid seals well. Some Vaseline might be necessary to ensure this.
To clean the filter itself, it is necessary to run the pump backwards. This is known as backwashing and is fairly easy, but can create a mess if not managed well before hand. When backwashing, the pump will expel water in a fairly large amount, so it might be necessary to attach a hose to the exit port unless the pump is positioned in a location that can handle excess standing water. Simply turn the pump off, pull the valve that reverses the flow of water through the pump, and turn the pump back on. The water that first emerges will be dark brown or grey. Run it until it is mostly clear, turn the pump off, switch the valve so that the water is flowing the ordinary direction again, and turn the pump back on. Turn the pump off again, set the valve to reverse, and turn the pump on again. Repeat this process until the water that comes out is clear.
After backwashing, it’s necessary to replenish the filter substrate, since most of it was just washed away. Diatomaceous earth is a common substrate, and should be added as a colloidal suspension. This means that it should be mixed with water before adding to the pool, so that clumps of mud do not form. Once the diatomaceous earth/water has been thoroughly mixed, set the valves so that the pump is drawing a majority of its intake through the skimmer. Turn the pump on, and pour the earth/water mix in.