Water Sort guide: empty tubes, partial pours and color planning
An empty tube is working space. Use it to expose a buried color or join matching top layers, then try to recover that space before opening another mixed stack.
Back to the game →Check the top color and free capacity
Select a source tube, then a destination. You may pour onto the same top color or into an empty tube. You cannot pour into a full tube or onto a different top color.
A pour moves as many layers from the continuous top-color run as will fit. If only one space remains, a run of two can pour one layer. It does not need to fit in full. Each successful pour counts as one move.
Give an empty tube a specific job
Before using an empty tube, name the color or buried layer you want to expose. Moving a mixed tube's top run out can open a useful match elsewhere. Moving the same run back immediately usually restores the same problem.
Bottom colors help you plan where a color may eventually collect, but they do not determine a fixed solution. Recheck after each pour. A promising receiving tube still needs matching top layers and enough capacity when you actually use it.
Worked example: only one layer fits
Read the illustrated tubes from bottom to top. A holds 2, 1, 1 and B holds 2, 2, 1. A's top run has two layers of color 1, but B has only one free space. Pouring A into B therefore moves just one layer.
After the pour, A is 2, 1 and B is 2, 2, 1, 1. B is full but mixed, so it is not finished. C holds 1, 2 and D is empty; together the example contains exactly four layers of each color. Numbers identify colors independently of the palette.
A → B: two matching layers, one free space
Distinguish a tidy tube from a completed tube
To win, every nonempty tube must be full with four layers of one color. Two half-filled tubes of the same color do not satisfy that condition. Join them when possible while keeping room to free other colors.
Finishing one color can simplify the board, but do not fill your last working space just to make a tube look neat. Compare the next legal pours before and after the move: exposing a new top color can be more useful than consolidating a color immediately.
Undo a move that removes all useful space
If no pour is legal, undo and inspect the move that used the last free capacity. A blocked board is recoverable through undo or restart; waiting will not change the tube contents.
Use a short loop: compare matching tops, check available space, predict the newly exposed color, then pour. The example's partial pour is legal but not automatically the best strategic choice. Legality and progress are different questions.