How to play water sort: rules and a three-step example

What is a water sort puzzle?

A water sort puzzle begins with colored layers mixed across bottles. Your goal is to separate the colors so each filled bottle contains one color. Empty bottles provide working space while you rearrange the layers.

In Bottle Harmony's classic puzzles, a completed board has full bottles of a single color, plus any remaining empty bottles. The regular bottles hold four layers. The smaller teaching example below uses two layers per bottle so you can see the whole solution at once.

When is a pour legal?

• The source must contain water. Only its top color can pour out; lower colors stay covered until you move what is above them.
• The receiving bottle needs room. You cannot pour into a full bottle.
• The receiving bottle must be empty or have a matching top color. For example, Blue can go onto Blue, but Blue cannot go onto Coral.

A pour moves a consecutive group of the same color from the top of the source, limited by the space available in the destination. You choose the source and destination; the game determines how much of that top group fits.

Follow a complete three-step solution

Read each bottle from bottom to top. Initially A holds Blue below Coral, B holds Coral below Blue, and C is empty. Each bottle has two spaces. The text labels let you follow the example without relying on color alone.

1. A → C: Coral is exposed at the top of A, and C is empty. Moving it uncovers Blue in A.
2. B → A: Blue is exposed in B. A has one Blue layer and one free space, so the colors match and the pour is legal. A is now full of Blue.
3. B → C: The remaining Coral in B matches the Coral in C. Filling C leaves A all Blue, C all Coral and B empty.

The board is solved in three pours. The empty bottle was not an extra destination to fill at random: it temporarily held Coral so the two Blue layers could meet.

This is a small teaching layout, not an app screenshot. On a larger board, the same legality checks apply, but more layers and colors mean you may need a longer plan.

How to use empty bottles well

Ask what a pour will uncover

Before moving a top color, look at the layer below it. In the example, moving Coral was useful because it exposed Blue, which matched the top of B. A legal move is more helpful when it creates another useful move.

Plan where a temporary color can go next

An empty bottle gives you flexibility. Filling all your free space with unrelated colors can leave you with no legal continuation. Before you use the last empty bottle, check whether you can soon combine a color or free another bottle.

Distinguish a tidy bottle from a finished one

A partly filled bottle containing one color is useful, but the board is not necessarily solved. In the example, C contains only Coral after the first pour, yet it still needs the second Coral layer. Continue until every nonempty bottle meets the puzzle's completion rule.

Check the top, not just the bottle's contents

A bottle can contain the color you want below a different top layer. That does not make it a legal destination yet. Uncover the matching color or use an empty bottle first.

Common mistakes when starting out

• Trying to pour onto a different color. Recheck the receiving bottle's top layer and free space.
• Expecting to pick a lower layer directly. Water pours from the top; you need to move the covering color first.
• Moving water back and forth without changing the position. Look for a pour that uncovers a useful layer or combines matching groups.
• Using every empty space immediately. Keep track of your next destination, not just the pour you can make now.

Undo is useful for comparing plans. When a sequence blocks your next move, step back and ask which pour used the space you now need. Restarting can also help you see the starting position clearly. These habits are practical starting points, not a guarantee of the shortest solution.

Common water sort questions

Why will the game not let me pour?

First check that the source is not empty, the destination is not full, and its top color matches the source or the destination is empty. Bottle Harmony's frozen-bottom bonus puzzles add a separate restriction: a marked frozen layer cannot pour until it is melted.

Can I pour part of a matching group?

A pour is limited by the free space in its destination. If the source has more consecutive top layers of that color than the destination can hold, only the part that fits moves.

Do I have to beat a timer?

Bottle Harmony has no countdown. You can plan your pours, use free undo or restart, and continue at your own pace.

Does the game work offline?

Gameplay works offline and does not require an account. Game progress is stored on the device. Supported mobile builds have usage analytics enabled by default and can send events when connected; see the privacy policy before installing.