*im not saying discontinue the fogger for good, just until you figure out the problem.

Also with the discontinued use of the fogger make sure your root zone is not drying out completely (Roots will not survive in dry conditions)

...lets see some more pictures! more detailed pictures of your set up and maybe a quick shot of inside your res. your kind of leaving us in the dark on what method of hydroponics you are using. sounds to me like a foggoponics//ebb-n-flow//dwc cross haha