FPS drops with unity pro water

Hello,

I've tried to search for solutions to my issue, but when I add one sample of "Unity pro water" to my scene, it runs fine other than random FPS drops every 10 seconds or so. Goes from 70 FPS to around 25 for a second.

I had the same issue with my old system, but I have very recently upgraded.

System Spec:

CPU: i5 3570k @ 3.4GHz GPU: Sapphire HD 7970 3GB RAM: 16GB 1600MHZ

Unity running from an SSD, along with the project file.

I'm thinking about using occlusion culling at the end of my development process, I can leave the water until the last minute but does anyone have a solution as such?