The quick answer
Rapid chlorine loss means demand is exceeding the amount available. Sun, algae, heavy use, debris, stabilizer and equipment can all contribute.
Confirm the test result
Use a dependable test and check at consistent times. Old reagents, weak strips or testing right after an addition can mislead.
Account for sunlight and stabilizer
North Texas sun destroys unprotected chlorine. Too little stabilizer leaves it exposed, while too much increases the effective chlorine needed.
Look for hidden demand
Early algae, dirty baskets, leaves, sunscreen and heavy swimming consume sanitizer before water looks green.
Check production and circulation
For salt pools, verify flow, cell condition, salt reading and output. For every pool, confirm normal return flow and schedule.
Correct the cause
Repeated additions without addressing debris, algae, stabilizer or equipment become expensive. Test the whole system.