Pour the colored liquids between tubes until every tube contains only a single color. Empty tubes act as temporary buffers — use them wisely.
Only the top layer of a tube can be poured. You can only pour onto a matching color or into an empty tube, and you cannot overfill a tube. Consecutive layers of the same color move together as one pour.
The selected tube lifts slightly to show it is active. Look for tubes with a large run of the same color at the top — they are ready to be poured to their destination.
Tip
Guard your empty tubes — they are your most valuable resource. Before starting a complex pour sequence, verify you have enough empty space to avoid getting stuck.
Water Sort requires planning several moves ahead under capacity and color constraints, training working memory updating, inhibitory control, and sequential planning simultaneously.