Why a normal Filter is not enough
The collected Beginner’s Guide distinguishes Allow and Block behavior and notes that Basic Filters mainly target solids. Water is a Liquid, so the relevant tool is an Advanced Filter rather than a normal solid-resource filter.
Configure the Advanced Filter
Set the filter mode to Block and choose Water as the selected resource. This means the selected Water is stopped while other material can continue through the path. The source does not directly publish the exact Wet Sand layout as an official recommendation, so this setup is an evidence-based application, not a quoted developer blueprint.
Avoid a misleading promise
Do not claim that a filter separates Wet Sand and Water by density or that one exact arrangement works in every mixed pile. Deep mixed piles and conversion behavior can affect results; if the current build behaves differently, the final layout needs 实机验证.