Blender Effector

Hey everyone, I’m a Blender novice working on an Andrew Price workshop,Create an energetic fire and water scene in Blender (1 of 4), Using Blender 2.91. I’m at the point that I can’t make the Effector solid so my simulated water penetrates rather than bounces off. I’ve added the Modifier Solidify but doesn’t seem to work. i’ve tried each of the parms, read the manual for this modifier but can’t seem to make it work. Can anyone help please and thank you.