Does your pool water returns slowly?
A swimming pool has a skimmer where the pool water goes into and from there into the filter and then back to the pool thru the return wall fitting. Have you noticed your return water flow is not as strong as it used to be? What could be causing this?
If you have a Cartridge Filter, when was the last time you changed or cleaned your filter? If you have a DE Filter, have you checked the grids inside lately? If you have a Sand Filter, when was the last time you changed or cleaned your sand? If you have maintained your filter properly, then this might not be your problem.
The sand in a sand filter needs to be cleaned with a filter cleaner at least once per season. In some cases you may need to do this twice per season. The sand itself (if cleaned regularly)
When you vacuum your pool, do you use a Skimvac that fits over top of your skimmer basket? By using this Skimvac, the basket can stay in place and trap any leaves or debris. If you do not use the SKimvac, you may have some debris trapped in the impeller of the motor in your swimming pool pump. This impeller has to rotate so many revelations per minute. Leaves and debris will slow this movement. Slow water flow does not mean your swimming pool pump is going bad. You need to check the impeller, the skimmer basket, the strainer basket in the pump, and even your plumbing lines.
When the water flow slows down, the filter and these other items need to be checked. Something is restricting the flow of water back to the pool. In most cases, this is simply an issue with a dirty filter or baskets, so check those first.