You can use the trichlor, but it will continue to make your cya get higher and higher and higher. Who knows how high your cya is?? A reading of 100 (since the tester cannot differentiate any higher) could really be 200? 300? ????? You can use the pucks but it is going to be hard to manage your pool. You will have to run extremely high chlorine to compensate for the high cya. Take a look at this chart:

Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

Trichlor pucks will not go bad as long as you keep them dry. You can put them away for the summer and save them to use next year if your cya level is low enough to permit it. Your call. I would not suggest continuing to use them but if you decide to, just be aware that your cl levels will need to be really high all the time and you may have a lot of trouble keeping this pool algae-free.

Liquid chlorine is not stabilized. You have so much cya in there already that you would not need to add more. (It does not go away. The only way to get rid of it is to drain and refill.) SWGs do not generate cya.

Hope this helps.