My pool has an attached spa with a spillover. Usually, the water level in the spa is several inches higher than the water in the pool, but for the last few days, the water level has dropped steadily during the evening after the pump has stopped running for the day. It seems like the water is draining back into the pool from the spa until the water level between the two bodies of water are at the same level.
Why has this started happening? Or, more importantly, why didn't this happen before? Is there a one-way valve that is supposed to prevent it?
Why has this started happening? Or, more importantly, why didn't this happen before? Is there a one-way valve that is supposed to prevent it?