Official Wiki
- Water can pass through a Filter but is blocked by Blocks, Conveyor Belts, Kinetic Presses, and Flux Emanators.
- Unsettled droplets evaporate after 45 seconds.
- Advanced Filters can process Water and other liquids.
Liquid · Density 100
Water drives the Wet Sand loop and several later reactions. Its level, spill path, and destination matter as much as its quantity, so treat every pool as part of the factory.
Working route
Surface lakes, underground layers, Ice, Steam rain, and Lumling are documented sources.
Water levels out across a plane and can leak through corner-to-corner block joins. Close the gap with an additional block.
Water turns Sand into Wet Sand and Wet Seed into its wet state. It also turns to Steam when it meets Fire.
The official Wiki documents a Cryoblaster-to-Snow-to-Steam-to-rain route. Route the rain back into a collection pool.

Evidence notes
These are useful player examples, not official specifications.