Water simulation hangs over the surface of the collision object I created a water particles but they seems to hang over the surface, why is this happening?


Still the water hangs over the ground even with Collision Surface Thickness zero:
Here is a fluid simulation with a liquid Effector Collision Thickness of 3 vs a Thickness of 0
 
and here is a domain where collision distance is too large and particle radius is rather large (2.0):

In other words, try dropping your collision thickness to '0' and particle radius to &lt; 1.0.