What if I make the water out of a cube (since it's supposed to be non-rippling water) and place it inside the tank, but set refractive index of the cube to be different from glass refractive index? I think I remember a refracting object once produced mirror-like reflection inside itself, but not sure if it works like this. So only one way to find out.Yes and as I mentioned above that is all going to depend on your material properties - primarily IoR and fresnel, then lighting, and the accuracy of the physics model within your rendering application.
What you need is a materials and fluid effects and lighting person to help with this.
If the materiel properties are set correctly on the acrylic and the water in the tank as well as the lighting the physics engine of the renderer should do the rest. Getting all the settings dialed in though, especially using MR, can be a bit of a black art.
That's not going to work... refraction is a factor, then there would be the need to continuously change the mirrors around with the camera angle...Fake it, put mirrors on the side and back some light fog and a few god rays for good measure..............dave