Build and care for an aquarium
Aquariums are built inside your own stable interior. Open the home icon's Stable interior menu and choose aquarium building. You place pieces in the world, using a transparent preview and your material count beside the pointer.
Make glass, then place cubes
One glass is fired at a Kiln from 6 Scrap + 1 Sap + 2 Water. It is a refined building material, not a new gathered resource.
A floor tile uses a 3×3 grid. The small piece is one third of a tile in width, depth and height; it is not 0.25 of a tile. A full 1×1×1 cube contains 27 small cells.
| Piece | Glass | Sap | Water to fill |
|---|---|---|---|
| 1/3 × 1/3 × 1/3 | 1 | 1 | 4 |
| 1 × 1 × 1 | 27 | 27 | 108 |
Select size, aim, place, repeat. The counter shows cost and stock, not a count of pre-crafted aquarium items. Touching faces merge into one tank and remove the inner glass. Build up to 5 full cubes high; upper cells need support. A single cube is solid and can be jumped onto. Keep the preview valid and clear of furniture and doors.
Tap E / Use near a tank to inspect it. Everyone can inspect. The owner can hold E to move it with a transparent preview and place it again. Moving keeps its contents; unsupported placement or a join that would bypass water requirements is refused. There are limits of 432 small cells and 48 aquarium fish per account.
Fill it before adding fish
Fill every connected cell. Each small cell holds 4 units of water capacity. Adding glass to a filled tank also needs water for the new space. The preview quotes the cost before placement.
Fish load grows with length: ceil(length in cm² / 100) water capacity per fish, minimum one. For example, a 10 cm fish needs 1, a 20 cm fish 4, and a 50 cm fish 25. A bigger fish needs a larger connected tank, and every resident adds to its load. The game checks the minimum physical fit as well, so do not assume spare water alone makes a tiny box suitable.
Care is a recurring material cost
Use the tank's care action to refresh it. A full tank uses 25% of its water capacity per change, rounded up. Missing water is added to that bill. Occupied tanks also consume straw and sap as feed ingredients: straw is ceil(total fish load / 20), sap is ceil(load / 40), each at least one.
Care is due every 2 days. A tank needs fresh water before adding a live fish. Living fish neglected beyond their 7-day deadline die and retain a poor condition / neglect record. Fresh water does not revive them. The deadline persists through logout and updates; moving fish around is not a way to reset it.
For a display that needs no living-fish care, use a trophy cube. It is a different item and stacks four high instead of five.
Reviewed 2026-09-27. Market prices and remaining world stock are live, not fixed by this guide.