Mission Pools Mission Pools Round Pool Gallons 12' 3568 15' 5310 18' 7646 21' 10407 24' 13593 27' 17204 30' 22302 Oval Pool Gallons 12' by 23' 7298 15' by 26' 10313 15' by 30' 12060 18' by 33' 15919