@Lisa723 Thank you for your thoughts. We definitely stay on top of the hot tub chemistry on a daily basis, and the water is always adequately chlorinated and crystal clear. Normally we have no issue with keeping the water balanced, however, we noticed that we could not regain balance after several bouts of "sexy time" in the hot tub, so we attributed our water balance issues to that. I totally hear what you are saying about there being many kinds of sex and not wanting to enforce things from that specific perspective. Hence my request for ideas. The problem I have with trying to inform guests via an information sheet (which I personally think should be a great way to deal with many issues) is that in reality, and my experience, most guests don't read anything that is more than a few words placed directly in their view. A lot of times, not even then.
Our hot tub helps my Airbnb stand out, and I attribute it, in part, to drawing guests to my listing over similar listings, so I would like to keep it on offer, however, just not at the time and cost expense of having to drain and refill it several times a month, when normally (when there is no sexy time going on), we only have to drain and refill on average, about every couple months.