Check the water jets in the pool to see if the water is flowing at the normal flow.

If you have an automatic pool cleaner and it has slowed down or stopped working, this is a sign that you may have some sort of filter or pump blockage.

Another way to check your water flow is to check the pressure gauge on your pool filter. Most pool filters have a pressure gauge attached to monitor the waterflow. When the pressure is higher than normal, this indicates that the filter may need to be cleaned or replaced.