I guess I am re-asking the OP's question, but I'm confused. According to TFP's "Water Balance for SWGs" webpage, TA should be 60-80. PebbleTec's support webpage for PebbleSheen says TA should be 80-120. My Pentair Intellichlor manual says TA should be 80-120. Are PebbleTec and Pentair assuming the use of pucks (like OP's PB)?