Aqua, if you have a little time, Richard (or one of the other 'chem geeks') will tell you exactly what's happening - I often need a beer or asprin to help absorb the info. The pH of the pucks is about 2.5 (which is very! low) so for every 8 oz puck you need to add ~4.5 oz of soda ash (pH plus) per puck to keep your pH within the proper range. (thanks Richard!)
In addition to the pucks constantly lowering the pH, they also raise your cya. Cya needs to be compensated for (see Ben's best guess chart; stickied at the top of the "using chlorine..." section of the forum) by adding more chlorine than your 'pool dude' would suggest.
Having added so much pH increaser, I wonder if your test kit is still good.
My best advice is to post a full set of numbers and see what the 'real' experts say, I might even be able to help, if I know your chem numbers