When you are not having to treat a problem, you want to raise it to the normal max, and let it cycle down toward the normal minimum. Given losses to swimmers and sunlight, it's pretty much impossible to maintain a 'constant' chlorine level in the pool. What you want to avoid is having it go below the minimum. It's better to be too high than too low, because pools are not especially forgiving, and a single algae episode can consume 30 days worth of chlorine!