Puzzle: Water Sort

Getting Started

The first pour

Puzzle: Water Sort presents you with a row of test tubes, each partially filled with layered bands of colored liquid. Your only action is pouring the top layer of one tube into another — and your only goal is to end with each tube holding a single solid color (or empty entirely). The rules take thirty seconds to learn. The later levels take hours to solve, because every pour is irreversible and a single wrong move can lock the board into an unwinnable state.

When you tap Play Now and load the first level, you will see four tubes — two filled with mixed colors and two empty. Tap a tube to select it, then tap another tube to pour its top layer into the target. The game enforces two strict rules: you can only pour the topmost color, and you can only pour onto an empty tube or onto a tube whose top color matches the poured color. Tubes have a fixed capacity, usually four units, and overfilling is blocked automatically.

Your opening routine

• Count the colors: Before your first pour, count how many units of each color exist. Every color must fit into a single tube — if a color has more units than tube capacity, the level is unsolvable and you must restart.
• Identify pure tubes: A tube already holding a single color is nearly complete — leave it alone unless you need its capacity temporarily.
• Reserve an empty: Always keep at least one empty tube as a buffer. Pouring without a buffer is the fastest way to dead-end a board.
• Plan two pours ahead: Before pouring, trace where the displaced color will go next. One-pour thinking causes cascading mistakes.

The first ten levels teach the mechanics with generous empty tubes and few colors. Use them to build the habit of pour planning: mentally simulate a pour, check that the resulting state has at least one valid follow-up pour, then execute. This habit alone will carry you through the mid-game levels, where the number of colors rises and the number of empty tubes shrinks to one or zero.

Core Mechanics

The pour engine

Puzzle: Water Sort runs on three interlocking rules: top-layer-only pouring, color-matching deposit, and fixed tube capacity. These three rules produce surprisingly deep emergent behavior, and understanding their edge cases is the key to solving the hardest levels.

Top-layer-only pouring means you can never access a color buried beneath another color without first removing the top. This is the core constraint that makes the puzzle non-trivial. Color-matching deposit means a pour only succeeds if the target tube is empty or its top color matches the poured color — you cannot mix colors in a single pour. Fixed tube capacity (typically four units) means a pour stops when either the source tube is empty or the target tube is full, whichever comes first.

The three rules in detail

• Top-layer-only pouring: Only the topmost color band is accessible. Buried colors require sequential removal of everything above them.
• Color-matching deposit: Pours onto mismatched colors are blocked. Empty tubes accept any color, making them the universal buffer.
• Fixed tube capacity: A full tube cannot receive more liquid. Partial pours are common — the source may not empty completely if the target fills first.

One subtle mechanic worth memorizing: when you pour from a tube whose top layer has multiple units of the same color, the entire same-color band transfers in a single pour, not one unit at a time. If a tube has two units of red on top and you pour it onto another red-topped tube with two empty slots, both red units transfer. This "band pour" is the most efficient move in the game and the foundation of advanced techniques.

Another important behavior: a tube is considered "solved" when it contains exactly one color and is full (or empty). A tube with three units of a single color is not solved — it can still receive a wrong-color pour and ruin itself. Never assume a near-complete tube is safe; protect it like an unsolved tube until it is literally full.

Intermediate Strategy

Color isolation

Intermediate Puzzle: Water Sort play is about color isolation: deliberately consolidating scattered units of one color into a single tube so the remaining tubes become easier to sort. The core technique is the reverse pour — pouring a mixed tube into an empty buffer to expose a buried color you need, then re-stacking the displaced colors back onto their proper tubes.

The trap at this level is buffer exhaustion. With only one empty tube, every reverse pour consumes your only buffer, and you must restore the empty before you can perform another isolation. The solution is to chain isolations: plan a sequence where the buffer is emptied back into a now-solved tube at the end of each cycle, leaving the buffer free for the next isolation.

Isolation patterns to memorize

• Reverse pour: Empty a mixed tube into the buffer to expose a buried color, then re-stack the buffer contents onto their matching tubes.
• Band consolidation: When two tubes have the same color on top, pour the smaller band onto the larger to consolidate into a single tube.
• Chain isolation: Plan isolation cycles so the buffer is restored to empty at the end of each cycle, ready for the next color.
• Solved-tube borrowing: A completed tube can be temporarily "borrowed" as a buffer if you immediately restore it — useful when no empty tube exists.

Another intermediate essential is color priority. When a board has five or six colors, do not try to solve them all simultaneously. Pick the color with the fewest scattered units and isolate it first — partially-solved colors free up tube capacity for the harder colors. Solving the easiest color first creates a cascade of increasing capacity that makes each subsequent color easier than the last.

Finally, learn to recognize trap states — board configurations that look solvable but are not. The most common trap is two tubes with mismatched top colors and no empty buffer to reverse either one. If you see this state approaching, abandon your current plan and prioritize restoring the buffer before it is too late. A trap state is a dead state; the only escape is a restart.

Advanced Tips

Solving locked boards

Advanced Puzzle: Water Sort play is about solving locked boards — configurations where every obvious pour leads to a dead state, and the only path forward requires a non-obvious multi-pour sequence. The key technique is the sacrifice pour: deliberately pouring a color onto a mismatched... well, you cannot pour onto a mismatched color, but you can pour a solved color out of its tube to create a temporary buffer, solve another color, then restore the sacrificed color.

The sacrifice pour is the most powerful advanced move because it converts a "solved" tube into a temporary second buffer. With two buffers, you can perform reverse pours that are impossible with one — exposing buried colors in two tubes simultaneously and re-stacking them in a coordinated sequence. The cost is move count and risk: if you cannot restore the sacrificed tube before you need it again, the board locks.

Advanced techniques to drill

• Sacrifice pour: Empty a solved tube to create a second buffer. Solve another color, then restore the sacrificed tube immediately.
• Band pre-stacking: Pour bands of the same color from multiple tubes onto a single tube in sequence, building a full solved tube in one cycle.
• Dead-state recovery: When a board locks, identify the color whose restoration would unlock the most other colors and sacrifice toward it specifically.
• Reverse-chain isolation: Use two buffers to reverse-pour two tubes in parallel, exposing buried colors in both simultaneously for a coordinated re-stack.

A final advanced concept is parity checking. Before committing to a complex sequence, count the total units of each color and verify they can physically fit into the available tubes given current capacities. If a color has five units and only one tube with three empty slots, no sequence of pours can solve it — the level requires a restart. Parity checking takes five seconds and saves you from wasting twenty moves on an unsolvable board.

Common Mistakes

What locks your board

The most common mistake is pouring without a plan. Players see a valid pour and take it, only to discover two moves later that the pour buried a color they needed and there is no buffer to reverse it. Every pour should be part of a planned sequence — if you cannot describe the next two pours after the current one, do not pour. Patience is the single most important skill in this game.

The second universal mistake is buffer exhaustion. The empty tube is your only escape hatch, and pouring it full of a color you cannot immediately remove again turns a solvable board into a dead one. Never pour into your only empty buffer unless you can see the follow-up pour that empties it again. If no such follow-up exists, the pour is wrong.

Mistakes that lock boards

• Ignoring color counts: Always verify each color fits available capacity before your first pour. Discovering a color is oversized at move 20 wastes the whole run.
• Hoarding partial tubes: A tube with two units of one color and one of another is not progress — it is fragmentation. Consolidate or isolate it before it traps you.
• Burying rare colors: If a color appears in only one tube, pouring another color on top of it buries it permanently without a buffer. Protect rare colors.
• Premature completion: Filling a tube to "solved" status before other tubes are sorted wastes a potential buffer. Sometimes a deliberately incomplete tube is more useful than a solved one.

A subtler mistake is misreading the band pour. Players assume a pour transfers one unit when it actually transfers the entire same-color band. This is usually good — band pours are efficient — but it can overfill a target tube you expected to have more room in. Always check the target tube's free capacity against the source tube's top-band size before pouring.

Finally, the most preventable failure is refusing to restart. When a board is locked, players burn five or six moves trying increasingly desperate sacrifice pours instead of admitting the board is dead. Learn to recognize a dead state instantly and restart immediately — the move you save by restarting is worth more than the moves you waste searching for a non-existent solution. A clean restart beats a hopeless salvage every time.