How to Play Aquarium
Fill aquarium tanks with water. The water level in each connected tank section must be consistent, and row/column clues tell you how many cells are filled.
Try it now — Easy 8x8 →The Rules
- Fill aquarium tanks with water by clicking cells
- Water fills from the bottom up — all connected cells at the same height in a tank are either all filled or all empty
- Row and column clue numbers tell you the total water cells in that line
- The water level in each connected tank section must be uniform
Available in 3 sizes (6x6, 8x8, 10x10) and 3 difficulty levels (easy, normal, hard).
See It in Action
Click cells to fill them with water — water fills from the bottom up within each connected tank
How to Play
- Read row and column clues to understand the total water distribution
- Identify tanks that must be fully filled or fully empty based on column totals
- Use the level rule: when a height within a tank is filled, all cells at the same height in that tank are filled
- Cross-reference row and column counts to narrow down which tank levels are filled
Pro Tips
The total of all row clues must equal the total of all column clues — use this to verify your progress
A column clue equal to the number of tank cells in that column forces all those cells to be filled
Think in levels: water in an aquarium always covers the lowest cells first and rises uniformly
Frequently Asked Questions
How does Aquarium work?
The grid is divided into aquarium regions. Water fills each region from the bottom up and must reach the same level in all cells of the same region at the same height. Numbers on rows and columns tell you the total filled cells.
Choose Your Challenge
Start with easy to learn the rules, then progress to harder difficulties.