John Schembri, owner of Clearview Aquarium Services in Sydney, has been installing aquariums in Sydney for the past decade for residential and commercial clients, both in commercial and office spaces.

Mr Schembri says the price of installing a larger aquarium can vary, however, a tank over four metres can leave a hole in a buyer's wallet.

"The total cost of the largest tank I have ever installed in a home is up to US$30,000. Depending on the size of the tank, you can put about 100 to 200 fish in it."

"During the pandemic I definitely saw a rise in the number of buyers asking for aquariums in their homes - mostly people who live around the city and have a bit of extra cash to spend."

A waterfront home in Sydney's south recently made waves on social media as it offered buyers the chance to buy a shark tank.

The two-bedroom, one-bathroom property at 63 Kangaroo Point was listed through McGrath's Kieran Bresnahan with a guide price of A$5.9 million.

The six-metre tank contains 20,000 litres of water and is home to 11 sharks, a grouper and two moray eels.

The owner, who wishes to remain anonymous, told the Daily Telegraph that he added the tank when he renovated the property a few years ago.

"The sharks were brought in from Cairns and most of them are tropical reef sharks. I get a lot of comments about how cruel it is to keep them in a tank that size. I had no previous experience of keeping fish before this tank."

Kieran Bresnahan of McGrath says the successful buyer of the property has the option to keep the sharks when they move into the house.

"I was curious to see if the property attracted buyers with its tank and waterside views. I had one online buyer tell me that the two bedrooms were perfect as they would be living alone, while another potential buyer said they would be looking to extend for their family."

Robertson Queensland

Sold in May 2017 for $325,000, this three-storey Brisbane mansion at 62 Janda St, Robertson comes with an in-ground pool with spa and a soundproof cinema with built-in speakers.

It also features a 5,000-litre tropical fish tank with a water storage tank for easier water changes.

Kewarra Beach QLD

Considered one of the most expensive homes listed for sale in Cairns when it is sold in May 2020, the property includes two swimming pools on different levels for buyers to swim in.

The property features an external pool with two garden feature ponds, one of which is heated to allow fish to live in it.

Port Lincoln SA

The five bedroom and five bathroom property at 16-18 North Point Avenue in Port Lincoln has a substantial salt water indoor aquarium with a variety of marine life.

Owners can sit in the living room of the house and enjoy a book while watching the fish swim by.

Glenhaven NSW

The 3.5m high saltwater aquarium at 28A Mills Rd in Glenhaven is located next to the glass wine cellar and was sold with the property in September 2021 for A$4.05 million.

The aquarium can also be seen while sitting in a home theatre with a night sky and footlights.

Kellyville, NSW

Described as a private retreat when it sells for A$2.65 million in April 2021, the four-bedroom, three-bathroom property at 49 Bruhn Circuit in Kellyville comes with a range of luxury design features.

It stands out on this list because it has two small sized aquariums, one near the living room and one near the stairs leading to the second level.