Hello, just purchased a new home with a pool. The current pool guy has maintained the pool for years and I went ahead and hired him to continue weekly visits. Last week my niece needed to do a science experiment and took some pool water to Leslie's for testing. The store said zero chlorine all other chemicals were in relatively good range, PH was slightly low. The pool looks sparkling clean and I saw my pool guy clean, add water, dump chemicals in the pool and replace chlorine tabs that morning. Concerned I took water to another Leslie location and got the same zero reading. I talked to my pool guy to report the zero reading and he was very surprised said the results where wrong the pool has chlorine in it. Concerned with my young children swimming in a pool with no chlorine. Could there be zero chlorine and no algae even after several days of zero chlorine. As a new pool owner with limited experience not sure who to trust. Thanks for any insight!