You as the home owner can perform “The bucket test” to find out if you do have a leak or if its just evaporation.
─ Bring pool water to normal operating level
─ Fill a bucket with water 3/4 full
─ Place bucket near pool (pool step is preferred)
─ Mark bucket water level on the inside of the bucket
─ Mark pool water level
─ After 24 compare the tow levels. If the pool water dropped more than the bucket water then most likely there is a leak in your pool.