K-Mart, CostCo, WalMart--these are the places selling the HTH Tri-chlor pucks loaded with copper. You'll have to go to a pool store if you want pucks. Here in NJ there are also discount pool/patio stores that sell proper tri-chlor pucks.

Of course, you could use bleach to chlorinate, add what CYA you need as a separate additive, and add muriatic acid to drive pH down as needed. Be the same as pucks only YOU will control how much CYA and the pH of your pool.