Why is my Camlock Filter is hard to connect? Sherralyn August 20, 2018 00:12 Updated Follow We suggest you check the check the bottom of the Filter to see if there is any plastic that needs removing from these threads. Related articles What is the difference between a camlock filter and a threaded filter? How do I install the Cam Lock Filter Adaptors to my filter box? Comments 0 comments Article is closed for comments.