I wouldn't worry about the TA for now--but I would go ahead and bump your Cl up to 3 ppm just to be safe. In my pool, 1.5 ppm Cl loss is negligible, but I don't know the average daily loss in a covered pool. If that's a much bigger chlorine loss than usual for you, you may need to shock it, but your CC is at 0, so I would just keep an eye on it. If the water starts smelling like chlorine, or if your CCs go up, or the water gets cloudy, then shock.

Janet