For the record, I actually think that using the Trichlor pucks until the CYA gets to the level you are looking for is the best way to add CYA, it kills two birds with one stone while your CYA levels are low. After understanding the TFP approach, anyone will realize that you can't rely on them exclusively and you have to stop using them at some point, but everyone here is aware of the CYA problem and can easily figure out when to stop using them and convert to bleach. Starting up with them reduces you chlorine budget for the time that you are using them, who doesn't appreciate that?