Are you using chlorine added manually after each soak? If so, then elevate the chlorine level so that it will last for the 3 days. Keep the spa covered and lower the temperature setting since that will have the chlorine last longer. However, if you have an ozonator it will use up chlorine a lot faster at least doubling the daily chlorine demand. If you have a way of turning that off, that would be best.
For 1 week, you could only use the elevated chlorine and reduced temperature approach if you didn't have an ozonator. With an ozonator, your're toast in that situation and would cross fingers that the ozone itself was sufficient to keep the spa in decent shape.
If you used bromine, then bromine tabs in a floating dispenser should last through a week. Or if you have an ozonator, then with a bromide bank it will make more bromine.
