Your pool is 12x22x9 how much water is in the pool?
Is there no shallow end? If there is no shallow end and the entire pool is 9' deep, the pool would contain 67280.8 litres of water (17773.57 US gallons)
length x width x height = volume
12 x 22 x 19 = 2376 ft³
2376 ft³ = 67280.8 litres (1 cubic foot = 28.316847 litres)