How do I make murky water that looks exactly like this?
You can do this using a volumetric shader.
If you are in Cycles, you can have both a surface and a volumetric bsdf in the same material:
Also, you will notice I use the shadow ray trick, because Cycles struggles with glass shadows and this will help prevent excessive darkness underwater.
The surface of the water remains white, the color is entirely from the volumetric shader.
If you are in Eevee, then you may need to add a separate volume cube under the water surface, or you risk having the volume poke through the surface.