New pool just filled yesterday. PB has a company coming out for the first week or 2. When they were here yesterday, I saw them add 2 ~32oz. bottles of a clear liquid. Unsure of what it was. Then I saw them add several gallons of muriatic acid. They did a bunch of prep to the pool pump, jets, etc., said to brush it 2 times a day and that they’d be back on Wednesday (tomorrow). Just to kill some time, I decided to test the chlorine, pH and “acid demand”. The chlorine test showed nothing. The pH test showed less than the measurable amount. The “acid demand” showed nothing, even after adding 20 drops of the solution. I was under the impression, by them adding the muriatic acid the first day, that they were using the acid start-up method but I’m unsure. The PB says he likes to start up pools really slowly so the plaster lasts but I saw them pour several gallons of acid in it. For a start-up of a new pool that’s only had chemicals in it <48 hours, what do these non-existent numbers tell you? Thanks!