I understand the no greater than 45 degree angle depth of footer to depth of pool without additional load bearing measures taken.
Most footers in Florida are 12” deep x 16 to 24” wide but with the house wall sitting right on the edge of the footer using block and fill. So 1’ deep footer out 4’ distance at 5’ depth. You can see below if a that’s not greater than 45 degree slope 1’ footer 4’ to 5’ depth pool
This is one of the reasons we don’t want a deep 6’+ pool within 5 feet of a house. The depth of the pool can impact the slope of dirt between footer and house and can cause the footer to fail.
I would never install any concrete pool within 10 feet of a house because a large percentage of concrete pools will crack within 30 years causing potential damage to the footer (there must be 100,000 concrete pools slowly leaking chlorine water into the ground table because they so expensive to patch). Or until the code changes to force an inspector onsite day of concrete pour to make sure the concrete passes a slump test and the concrete crew is covering the concrete with plastic and watering it for 7 days and not coating it with anything for 28 days for off gassing to complete and cure which is how long all lime based concrete needs to cure before coating and you can never have a concrete pool done within 30 days (I laughed at 30 day concrete pool company that just went out of business, and ashamed it was even allowed as no concrete manufacturer allows concrete coated with waterproofing that fast. How does it off gas and cure when coated with waterproofing?). But as the largest fiberglass pool manufacturer and installer in the state of Florida, I would easily put a fiberglass pool within 4’ of a footer. Our pools have a larger 8”x10” apron 3500psi with fibermesh footer poured around it unlike most concrete pools only have 5.5” thick.