Water tank is a logic puzzle game that uses simple rules to complete challenging puzzles Game rules 1. The game board is divided into several pieces, each of which is called a "water tank" 2. In the game, you can fill each water tank with some water or leave it empty 3. The water level in the same tank is equal. That is to say, cells in the same row of the same water tank either have water or are empty. 4. The number outside the chessboard is the total number of cells filled with water for that row or column.