At one time, many people had aquarium at home. If they are like myself, this hobby didn't last for too long as it was very frustrating and not as easy as it seem. However, if one is successful in keeping those fish, it can be very rewarding. I think the major failure is the "know how". The people selling pet fish concentrate on selling but not on education. So soon, the hobby dies and so is their business.
Little maintenance is required, no pump, no filtration, hardly any food is given as I think I have created a natural eco system for them to survive. I found that my dogs also drink from the tank and I topped it up all the time with rain water.