Aquarium Solving Tips
Aquarium is about letting one mark cascade through a tank. New? Read the rules first.
1. Zero and full lines
A row or column with 0 is all air; one whose count equals the grid size is all water. Mark them and spread.
2. Spreading
One wet cell makes its whole tank row wet and every tank row below it wet. One air cell makes its tank row air and every tank row above it air. Follow each mark to the end before moving on.
3. Tall tanks
A tank that spans many rows can only be filled to a few levels that fit the column counts beneath it. Try each level against the column it dominates.
4. Row budgets
Add up the tank segments in a row. If the count can only be reached by wetting a particular segment, that whole segment (and the tank below it) is water.
5. Air is information
Marking air is as powerful as marking water: it caps the tank and frees the rows above. Don't leave known-dry cells blank.
6. The last tanks
When a few tanks remain, each has only two or three possible levels; test them against the remaining counts and the puzzle collapses.
Frequently asked questions
Where do I start an Aquarium puzzle?
With rows or columns whose count is 0 (all air) or equals the size (all water), then spread each mark through its tank: air spreads upward and sideways within a tank row, water spreads downward.
Last updated 2026-10-21