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Aquarium Puzzles for Beginners: Start Here

New to Aquarium? Learn the two rules on a 6×6, then get used to two ideas: counting each row and column, and letting water lie flat, so it spreads across its tank and down, while dry spreads up. Those two finish most Easy levels in the game. This page puts the guides in that order, with a six-line warm-up to check yourself before you move up a size.

Open Aquarium full screen for more sizes, saved progress and best times.

Your path, in order

  1. Learn the rules. The Aquarium rules page solves one of the game’s Easy levels step by step. The one idea to take away: each row and column holds its number of water squares, and water in a tank is level, filling from the bottom.
  2. Solve your first 6×6 from the 0s and the 6s. A row numbered 0 is all dry; a row numbered 6 is all water.
  3. Let the water flow. Every water square fills its tank across and down; every dry square dries its tank across and up.
  4. Count every line. When a row or column has all its water, the rest is dry; when it has just enough room, the rest is water.
  5. Do the warm-up below. Six lines, each practising an idea from the guides above.
  6. Learn the other techniques. How to solve Aquarium covers all six; too much water and no room come up on bigger grids.
  7. When a puzzle goes wrong, read the six common mistakes. The big one is filling a tank before it’s certain.
  8. Move up a size when you’re ready (see below).

Warm-up: six lines

Each is a single row or column, crossing a few tanks, with its number. Work out what you can be sure of from that line alone, then open the answer. Every answer is everything the line can tell you on its own.

1. Five out of six

Warm-up 1: Five out of six A row of six numbered 5, crossing three tanks: one square, then two, then three. What can you be sure of? 5
Show the answer
Warm-up 1, answered A row of six numbered 5, crossing three tanks: one square, then two, then three. Certain: square 1 dry, square 2 water, square 3 water, square 4 water, square 5 water, square 6 water. 5

The single square on the left is dry, and the rest hold water. The row’s tanks have 1, 2 and 3 squares in it, and each is all water or all dry. Leaving out the 1 is the only way to make 5.

2. Just one

Warm-up 2: Just one A row of six numbered 1, crossing three tanks: two squares, then one, then three. What can you be sure of? 1
Show the answer
Warm-up 2, answered A row of six numbered 1, crossing three tanks: two squares, then one, then three. Certain: square 1 dry, square 2 dry, square 3 water, square 4 dry, square 5 dry, square 6 dry. 1

Square 3 holds water, and the rest are dry. The other tanks have 2 and 3 squares in the row, too many for a 1.

3. Making four

Warm-up 3: Making four A row of six numbered 4, crossing three tanks: three squares, then two, then one. What can you be sure of? 4
Show the answer
Warm-up 3, answered A row of six numbered 4, crossing three tanks: three squares, then two, then one. Certain: square 1 water, square 2 water, square 3 water, square 4 dry, square 5 dry, square 6 water. 4

Squares 1 to 3 and square 6 hold water; squares 4 and 5 are dry. The runs are 3, 2 and 1, and the only way to make 4 is 3 + 1.

4. One in a column

Warm-up 4: One in a column A column of six numbered 1, with one tank in its top three squares and another in its bottom three. What can you be sure of? 1
Show the answer
Warm-up 4, answered A column of six numbered 1, with one tank in its top three squares and another in its bottom three. Certain: square 1 dry, square 2 dry, square 4 dry, square 5 dry. 1

Squares 1, 2, 4 and 5 are dry. Water fills a tank from the bottom, so if the top tank holds the column’s one water square, it’s in square 3; if the bottom tank does, it’s in square 6. Either way, the other squares are dry, but this column alone can’t say which.

5. Five in a column

Warm-up 5: Five in a column A column of six numbered 5, with one tank in its top three squares and another in its bottom three. What can you be sure of? 5
Show the answer
Warm-up 5, answered A column of six numbered 5, with one tank in its top three squares and another in its bottom three. Certain: square 2 water, square 3 water, square 5 water, square 6 water. 5

Squares 2, 3, 5 and 6 hold water. Five out of six means one tank is full and the other is two deep, filled from the bottom. Either way round, the bottom two squares of each tank hold water. Squares 1 and 4 could go either way.

6. A tall tank

Warm-up 6: A tall tank A column of six numbered 4, with one tank in its top two squares and another in its bottom four. What can you be sure of? 4
Show the answer
Warm-up 6, answered A column of six numbered 4, with one tank in its top two squares and another in its bottom four. Certain: square 5 water, square 6 water. 4

Squares 5 and 6 hold water. The top tank can give at most 2 of the column’s 4, so the tall tank gives at least 2, and its water starts from the bottom. Nothing else is certain from this column alone.

When to move up a size

You’re ready for Medium (8×8) when you can finish Easy levels without guessing, you spread water and dry without thinking, and you count columns as easily as rows.

The bigger sizes don’t just take longer; they ask for more. On Medium, 41 of the 50 levels need too much water and 21 need no room. On Hard (10×10), every level needs both, 42 need every arrangement of a line, and 39 need what-if.

Next steps

Questions

Is Aquarium good for beginners?

Yes. The two rules take a minute to learn, and 32 of the game’s 50 Easy levels finish with just two ideas: counting each line, and letting water lie flat.

Do I need to be good at maths?

No. There’s no adding beyond small numbers: how many squares in a row or column hold water.

How long should a puzzle take?

As long as it takes. PeerPuzzles keeps your best time for every level, so you can see yourself improve without trying to.