Multiport, push/pull valve, and diverter are all commonly used names for the little "thingy" with a handle that sits on top of or hangs off the side of most filters. Their function is to direct the flow of water inside, or outside, of the pool filter.

To normally filter the water in the pool, and keep it clean and clear, select "filter" - which will allow the water to pass through the multiport, into the filter elements, clean the water, and travel back into the swimming pool.

When the pool filter is dirty, and it's time to clean it, you can "backwash" the filter. This stirs up the water inside the filter and sends out dirt and debris from the backwash line After backwashing, you should always "rinse" the filter.

Another option is "waste" which takes the water and sends it through the multiport and out the backwash line, completely by-passing the filter tank. This is used when the pool is extremely dirty and you don't want to send the water back into the pool while vacuuming.

It is very important that you turn your pump off before you turn the multiport handle or move the push-pull valve. Forgetting to turn the pool pump off will result in serious damage to the multiport or push-pull valve.

Side-mount Multiport They are found commonly on sand filters on in-ground swimming pools.

Push-pull Valve Pull it up and water goes into the filter to be cleaned and put back into the pool. Push it down to backwash the filter.

Top-mount Multiport Most above-ground pools and some in-ground pools use this to control the water flow through their filter.