Ok so my contract says im suppose to have the hayward pro series 36" sand filter system and i hit up the pb today because the one that he has on my pool is the 310 , not to mention the top is leaking cuz it has a crack in it, so he tells me no i think its suppose to be the 310, because its 36" but when i measured it its only 31" so im assuming the 360 is 36" like i was suppose to get . Anyways i called hayward but they said id have to call tech support and they are closed already, anyways just wondering if anyone knew the difference in size , if the 360 is 36" or not thanks