We purchased a home at the end of the season which came with a freshly built ~26k gallon in ground pool. The equipment includes a Pentair 320 auto chlorinator which I’ve been adding chlorine pucks too. The water is crystal clear right now (paid a company to open the pool a few weeks ago). Using the TF-100 testing kit the chlorine level keeps falling. The test block level is showing 0.5 (free or total chlorine?) and the ph has consistently been 7.3. I’m new to owning and managing a pool. I’ve converted the Pentair auto chlorinator to top feed from bottom feed which seems to have helped a little bit. However the pool is not consuming the chlorine pucks fast enough. How can I get the chlorine level higher? Is shock my only option? Is there anything to look for when selecting a shock to use?