Last year I was traveling a lot for work Monday to Friday so there were many weeks that I closed the pool. My pool was very stable in terms of chemistry, so I figured out in advance how much chlorine I needed to add before I left to ensure that my chlorine level would be sufficient until I returned. I put the cover on set the filter to run 4 hours per day and it was spot on when I returned.
Later in the summer I started to worry about what would happen if something unexpected (branch falling on pool, neighbors lawnmower kicked up a rock, etc.) caused the water level to fall below my intake, and the resulting damage to my pump. So then I decided to leave the filter off for the 5 days I was away. I added my calculated quantity of bleach on Sunday night while the filter was running and made sure it was well circulated before I turned it off. Again, there were no problems when I returned.
This may not be the approved method, but it worked for me.