reflexion is inversed (try with a non circular mesh)
don't know yet how to fix it

OK. Then if the mesh must be reversed (mirrored), place the camera right above it. Works for uniform meshes only though

It´s working now but the Rendertarget doesn´t show up until rt_mesh or rt_waves is removed and readded.

nice. Reload rt is maybe a bad stack order of entire scene.

, great hint, exchanged reflect and world.

excellent

Yeah. Good work!
PS I would never have guessed that changing places of ops above Add might help...

op order is important in many ways, using blend for example.

I thought it was not the case with Add (if my memory serves me right, the only exception being ModMisc...).
Thanks, anyway.