Wierd pool waves..started by itself.?

Question

ok this pool we have started swelling into the center then swells to the sides. kinda like waves but it goes to then center then it goes to the sides then back to the center...we have no idea how it started. But it wont stop it has been doing it for a while now. any suggestions with what it is and how to stop it?

Answer 1

Could it be some kind of blocked filter affecting the flow of water in and out of the pool?