*** got a 10gal hospital tank, but then again, I keep a south american dwarf cichlid community, so I usually dont have too big of fish.
I have a siamese algae eater as a cycle fish in there, but thats mainly because it cant be kept in the main tank and I dont have the heart to get rid of it. Since its a small tank, but mostly empty, I do water changes every so often (usually when I notice that the water level has dropped significantly). When I have stock in there, I perform them once or twice a week to make sure everyone is happy during the quaranteen period.
Right now, the tank is in my basement which is unfinished. My eventual plant is to finish off the basement, and give the tank a nice look to it. Plant it out and keep one or two smaller fish in there, like a betta or some killies so that they can keep it cycled, and ready if needed, but the tank can look nice in the mean time. Of course, you run the risk of killing, injuring, or sickening your cycle fish, but if you dont keep fish you are very partial too, it shouldnt be too much of a loss.