The fastest way to get better at Aquarium is to count every line after every move, mark dry squares as carefully as water, and keep an eye on tall tanks, where water runs down a column. We measured these tips on all 150 of the game’s levels, and the numbers below come from those tests.
These build on how to solve Aquarium. If you haven’t played before, start with the rules.
Solving tips
1. Start with the 0s and the full lines
A row or column numbered 0 is all dry, and one numbered with its full length is all water. 101 of the game’s 150 levels have at least one: 44 of the 50 Easy levels, 35 Medium and 22 Hard. They’re free moves, and the water and dryness they create spread straight into the tanks they cross.
2. Follow what you just changed
Every move changes some rows and columns, and those are where the next move usually is. On the game’s levels, the next move is in a row or column the last one touched 87% of the time on Easy, 81% on Medium and 72% on Hard. Count those lines again before searching the rest of the grid.
3. Mark dry squares as carefully as water
About half of every solution is dry: 51% of the squares on Easy, 50% on Medium and Hard. Dry marks aren’t just tidiness. A dry square dries everything above it in its tank, and the dry squares in a line are what tell you it has just enough room left.
4. Small numbers: watch for too much water
When a row or column has a small number, look at the tanks crossing it. Water can’t go in one square on its own: it brings its tank’s whole row, and everything below. A big tank row, or a tall tank in a column, is often too much, and that square is dry.
5. Big numbers: watch for no room
When a line needs almost all its squares, ask which ones it can’t do without. Keeping a square dry dries everything above it in its tank, and that can leave too few squares to reach the number. Then the square holds water.
6. Don’t forget the columns
Columns are where water runs down a tall tank, so they’re where too much water and no room do much of their work. On Hard levels, 55% of the too-much-water moves and 59% of the no-room moves are about columns. On Easy, it’s about a third.
Tips for playing on PeerPuzzles
7. Tap to fill, again to dry, again to clear
A tap fills a square with water, and the water flows: across its tank row and down through the rows below. Tap again to mark it dry, which dries everything above it in the tank. A third tap clears it. On a computer, right-click goes the other way, and Undo (or Ctrl/Cmd + Z) takes back a move.
8. Let the numbers and Stuck? help
A row or column number turns teal once it’s met, and red when it can’t be: too much water, or too little room left. And if you’re stuck, Stuck? (or H) highlights where to look and names the technique, without filling anything in for you. If one of your squares is wrong, it rings that square first.