You can, but remember that the pucks (trichlor) contain cya and thus will cause your cya level to rise which in turn will require you to maintain higher chlorine levels to keep algae at bay. They are also very acidic and will drive your ph down. If you cannot find anybody to throw some bleach in every few days while you are gone and do have to use the pucks, be sure to check your cya level when you return and then adjust your required chlorine levels. Also, before you go, take your ph level up to maybe 8.0 or so to give it some room to fall without dropping below 7.0 before you return.

Someone else may chime in here with more advice for you. I know that Al, (Poconos) was out of town recently for several weeks and did use pucks. Maybe he can give you some more specifics about what the change in his cya and ph levels were during that time.

Good luck.