This pool can hold up to about 7,181 gallons of water.
It depends how deep it is.
26700 gallons
You didn't mention shape, however if a rectangle it would be approximately 7,300 gallons
Based on a rectangle. approx 20,250 gallons
If the tank is a cylinder, 72 feet in diameter and 4 feet deep, that works out to 121,827.862 U.S. gallons. 1 U.S. gallon is exactly 231 cubic inches, so a cubic foot is about 7.48 gallons.
Assuming it is a rectangle, 56.232 imperial gallons
You would have to know how deep the tank is.
1,615.79 US gallons.
If the bottom of the pool is a uniform gradient from one side of the rectangle to the other, then volume = 2625 cubic feet = 16351 gallons.
3.246753 gallons
398.7 gallons.
About 7,100 gallons of water.