Sudoku and Aquarium are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Aquarium is distant to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: Rectangular, aquariums
- Closeness to Sudoku: Distant
What is Aquarium?
Fill aquariums with water so that within each one the water settles to a level, and the edge clues count the water in every row and column. Here are the rules in full:
- The grid is divided into aquariums; you shade cells to show water.
- Within one aquarium, water finds its level - a row of it is either all water or all air across that aquarium's width.
- Clues on the edges count the shaded cells in each row and column.
See an Aquarium grid
Aquarium shades cells as water, which settles to a level within each aquarium, while edge clues count the shaded cells per row and column. Below, water (blue) has filled the lower rows, air the top.
Water (blue) settles to a level; edge clues count the shaded cells.
The row and column counts drive placements the way Sudoku clues do, and it is a single-solution logic puzzle. But you shade water rather than place digits, and the water-level rule has no Sudoku equivalent - a distant relative.
What Aquarium shares with Sudoku
- The row-and-column counts drive placements much as Sudoku clues do.
- It is a pure-logic, single-solution puzzle solved by elimination.
How Aquarium differs from Sudoku
- You shade water, not place digits, and the grid ends black-and-white.
- The water-level rule inside each aquarium has no Sudoku equivalent.
Do Sudoku skills transfer?
No digit technique transfers, but the count-driven elimination - "this row still needs three shaded and only three fit" - is the same instinct a Sudoku hidden single trains.
The verdict
Aquarium shares Sudoku's line-counting logic but resolves into shaded water, not numbers.
Where to play it
If it was Sudoku you came for, the level is the choice that matters more than the variant - Aquarium and Sudoku part ways on the rules, but a Sudoku grid can be a two-minute warm-up or an hour of work depending on nothing but how much of it you are given.
Difficulty and type are two separate dials here: the type sets the extra rule, the level sets how much of the grid you start with. Easy Sudoku leaves 36 of the 81 cells filled, so there is always an obvious next move somewhere; Evil Sudoku leaves 23, with no easy moves at all. Take it at the gentler end while the pattern is still new, and move up once it stops being a fight.