In my node editor I have the following Materials set for the water which is made with a fluid simulation.
In the preview window it looks like this (Which is how I want it.)
Then when I render out the image it looks like this (Not how I want it.)
Below are my render settings
I tried detaching the glass node and I still got the see through look. I tried closing and reopening the project file. I tried changing the camera too incase I messed something up with the lens. I can't seem to figure out what's happening and how to fix it.