Post-process: Material with screen distortion affected by depth

Hi guys, I’m trying to create an underwater effect using a post-process material effect, I managed to get the effect working. I’m trying to create the effect so it’ll affect the scene more in the background using a Depth Fade node, so it’s very light in the foreground and strong as it gets farther from the camera.
The problem is that after multiplying or lerping the effect with the Depth Fade it creates a weird duplicated effect or ghosting instead of just distorting the image more as it gets deeper. If I don’t use the depth to create this effect is fine. Blending is done before Tonemapper BTW.
Any solutions to this?
This is the effect and the material node editor:

You are welcome