50K gallons is a HUGE residential pool, and very unusual. A 30 x 60 lap pool with 4' ends and a 5' center would be only 57K gallons; a 20 x 40 block wall pool with a 4' shallow end, 12' flat deep end, the break at 10' from the shallow end and a flat bottom straight wall deep end would be only about 45K gallons.

Please measure the pool's dimensions. It's hard to dose correctly, with incorrect volume calculations -- but about 30% of pool owners use seriously incorrect values.