Those trichlor pucks cause a lot of unsuspecting pool owners to have too much CYA in their pools. Just don't use them anymore. A CYA reading of 70 will work fine. You'll just need to maintain adequate chlorine levels per the Best Guess Chlorine Chart in my signature.

Keep adding the Borax. A reading of 6.8 is the lowest a pH test can register so in all reality, it could be lower than that. After adding Borax, wait a couple of hours to let it circulate, then retest and redose.

FC + CC = TC, so your chlorine numbers aren't quite right. How are you doing your chlorine test?

As far as adding bleach to the skimmer, that is fine and how I always add mine. Just pour it slowly while the pump is running.

Please add the fact that you have a K-2006 to your signature.