Not sure the gallons. It is 12x24 starts at 3ft and descends to about 6ft. It is an IG. plaster. Hayward star clear plus cartridge filter, Hayward max-flow xl pump, fill pool with city water. And also have a Hayward chlorine feeder. Model# cl200. Also have a polaris pressure cleaner booster pump. Water level is fine, and no bubbles in pump filter and still air when i turn the polaris pump off. LOST AND CONFUSED where the air is coming from.