Experimenting in After Effects. Trapcode Form and Shine create the water and light rays shining through. Particular particles show up only within the light rays. Many 2D images of aquarium plants are distributed through 3D space to give a sense of depth. An adjustment layer with several duplicated turbulent displace's to make it feel like the water is distorting your vision. A few lights and depth of field add to the sense of realism.