I bet if you lived in the right market, you could make quite a business of installing and maintaining aquariums. You could probably charge a premium per hour too because it must be tough to learn how to do this right.
Money.com - The latest must-have hedge fund accessory weighs a ton (literally), contains up to ten living creatures, and costs $600 a month - just for upkeep.
Aquariums, which were popular in the 1970s, are back. But forget the fish tanks in your dentist's office - these "installations," as they're called, take six months to complete and cost as much as $600,000.