Isosurface extraction based on condition

These are isosurface with plot of alpha_water on them. How to remove the surface that is fully blue(alpha_water<0.2). If the surface has mix of blue and red I need those surfaces. In “Find data” tool we can choose cells/points with a condition similarly is there a tool to choose a surface with a condition?
Here is the plot:

use Treshold filter.

Thanks but it also removes the surfaces having both air and water.
Here is before threshold:

Then after applying threshold 0.5 to 1, surfaces completely blue is removed but also the one with mix of red and blue which I need

What is your question here ?

Sorry, so in this plot I have multiple 3d surfaces. For coloring I plotted the alpha_water on them. There are surface which has red and white colors which indicate pure water (category 1) , there are surfaces with blue and red which indicate water and air(category 2). Finally third category which is completely blue that is fully air. I have to remove last category surface and keep the other two.

Uncheck “All Scalars”

1 Like

Thanks, I think it worked. What does "All Scalar " do?

If the value of this property is 1, then a cell is only
included in the output if the value of the selected array for all its
points is within the threshold. This is only relevant when thresholding
by a point-centered array.

Just hover with your mouse on the option to see the tooltip documentation.
Alternatively, click on the ? button.

Sure, thank you