Aquariums are great showpieces, but they’re tricky to look after. This is like the idea that there are companies which “hire out” office plants and do all the work of picking them up a few weeks later and changing them over to keep the place looking fresh and changing.
So what you do is you have a mad marine aquarium setup in the foyer or reception area. Every month say, you go in and change the fish, change the structure of the rocks in there, maybe move the pump to the other side and voila. A fresh new look. They get a cool aquarium without needing to look after an aquarium. And it changes every month or so.
You might need to get them to feed once a week.