With 42.8% of homes here owned outright and a median age of 53, a lot of Dicky Beach pools have been in the same hands for a long time — long enough to have changed sanitiser systems at least once. That is where most persistent water problems begin: a pool converted years ago, still dosed on the assumptions of the system it used to have.
The three systems are genuinely different in how they behave. A salt pool generates its own chlorine continuously and drifts alkaline as a consequence of how the cell works, so regular acid dosing is normal rather than a fault. A pool on liquid chlorine has no stabiliser coming in with the dose. A pool on stabilised granular chlorine is adding cyanuric acid every single time it is dosed, whether the owner intends it or not.
Applying one system's target ranges to another is the single most common fault we see here, and it is invisible without a test.