Water Refracts Light Through Floor

[Teriander]

I've been having an issue where my water appearing to "float" off the surface of my floor. To fix this, I lowered my Simulation about 4" after it finishes calculating. When I render after doing this my room gets crazy bright, as if my GI is bouncing everywhere.

The problem is, now that my water is on the floor, the geometry from the water is picking up light (vraysun) on the other side of the floor, and bouncing that around in my room because the water is refractive. I've tried extruding my floor to make it have thickness, and now the water is bouncing around black because the space inside the floor is now black.

Any suggestions to get the water to attach to the floor surface without picking up light under the floor?

[Ivaylo Katev]

i'm not sure where the problem is, can you attach one image to see what is happening?

[Teriander]

Here are two examples rendered at a low resolution. The first render is more of what Im trying to get, except the water is floating above the floor. The second render is the PhoenixFD lowered about 4". Its on the floor, but light from outside is bleeding into my scene.

[Ivaylo Katev]

i see, so the problem is that the parts under the floor are directly illuminated and the caustics are visible over the wall. i think the solution is simple - just made the floor opaque in both directions, now it is transparent seen from the back.