Expert 3D Blender Designer Required

We require an expert in Blender 3D. We have a project that is almost complete but having an issue trying to simulate clear glass which is a key feature of the project. So the first task is to look at the existing files and see if they can be improved. We have a main image and in front of the main image are small glass moving squares. We need these to be crystal clear rather than a grey tint.