I guestimated my pool size. I log in what I add and the test results. Can pool math then say - sorry based on the math your pool size is not x it is y?
Test FC and/or pH. When you need to change FC or pH, then make the change (addition) and measure result 30 minutes later.
Use the effects of adding, enter exactly what you added to by pool (chemical and amount). Modify the pool volume until the change that you saw matches the pool math calculation. That is close to your pool volume.
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