Jam Jar Fish Tank
Jam Jar Fish Tank, more commonly known as the aquarium, is an underwater building that can be constructed on the Home Island. Players can deposit fish and monsters that they have collected into the aquarium, which then generates passive income. The larger the fish and monsters in the aquarium, the more income that is generated. Players can visit their aquarium and watch the fish and monsters swimming around in the individual tanks for each destination.
There is an upper limit to the amount of coins 
generated by the aquarium based on the number and size of the fish and monsters that it contains (approximately 24 h after the last collection). Moreover, the generating speed will gradually slowing down if coins keep accumulating. Thus, it is recommended to collect the income from the aquarium at least twice a day (the more frequent, the better) to ensure that no income is lost and make the most profit.
When the player has a fish in their bag that hasn't been added to the aquarium yet, there will be a red notification above the aquarium indicating that this fish can be added. Also, when the player have a fish with more stars in their bag than the one already in the aquarium, that fish will displayed on a dark grey background and have an aquarium mark in the info panel.
Creatures (currently not every species, listed below) could be kept in the aquarium since the 2.54 update.
Requirements: Character level 4
Marina Aquarium Upgrades:
Level 1: 10 Sea Grass
Level 2: 20 Sea Weed
Level 3: 30 Volcanic Rock
Construction costs:
Level 1 (Paradise Island): 25 
and 3000
Level 2 (Great Lakes): 10 and 1000
Level 3 (Costa Rica): 15 and 1500
Level 4 (Alaska): 20 and 2000
Level 5 (Australia): 25 and 2500
Level 6 (Scotland): 30 and 3000
Level 7 (Thailand): 35 and 5000
Level 8 (Amazon): 35 and 10000
Placeable Creatures + Trash:
| Icon | Location | Creatures placeable in the Aquarium | Trash placeable in Aquarium |
|---|---|---|---|
|
Paradise Island | Red Starfish, Flower Tube Sea Anemone | - |
|
Great Lakes | Bullfrog | - |
|
Costa Rica | Pacific Land Crab, Nudibranch | Inflatable Flamingo |
|
Alaska | - | Harpoon |
|
Australia | Pinctada, Purple Sea Urchin, Sand Anemone, Sand Cucumber | Surfboard |
|
Scotland | Palmate Newt | Nessie Toy, Excalibur |
|
Thailand | - | - |
|
Amazon | - | - |
|
Chemical Plant | Toxic Puffer, Cybersquid, Firetopus, Lemon Pufffrog, Sewage Fungus, Plasmaturtle | - |
Marina Aquarium[]
Paradise Island Aquarium[]
Great Lakes Aquarium[]
Costa Rica Aquarium[]
Alaska[]
Australia Aquarium[]
Scotland Aquarium[]
Thailand Aquarium[]
Amazon Aquarium[]
Chemical Plant Aquarium[]
Secret Aquarium[]
