Ah...The NICE thing about using Tri-chlor pucks when you have no CYA is that the CYA builds up slowly, but the pucks maintain a steady flow of chlorine during that time--so if it it's being consumed, it's always being added as well. But if your pH is low you need to boost it with borax. Also, be absolutely certain that the pucks do NOT contain copper--no matter what the pool guys tell you.

The advice they give you about adding most chems seems to be depressingly utter nonsense most of the time.

Or you can just do it Watermom's way and add bleach, CYA and baking soda as needed.

But be careful on the last--absolutely do NOT add baking soda until you test your Total Alkalinity--our public water comes out at 180-185ppm of T/A. You do not want more than that in a vinyl pool, and in a plaster/concrete pool you must immediately begin the lowering regime.