Unfortunately, you will need to run the pump occasionally. Daily. But you won't need to run it as often as if it were being used. Swimming in it uses up the chemicals as opposed to no use. I suggest that you set your timer for at least one hour per day (I suggest 2 hours) otherwise the pool WILL turn green if it is stagnant and no circulation even if chlorine is in it. The cost of running the pump an hour or so a day verses letting it sit for an entire summer, the cost of restoring it back to swim-able condition could be very costly depending on how bad it gets. May need to be drained, acid washed and refilled.
So my over-all advice would be... Run the pump at least an hour a day...Check the chemicals two to three times a week. Will not require much chlorine if you are circulating it daily. Hope this helps. Rob