my PB came by over the weekend to fix a problem with my heater. Today as I was working in the pool area, I noticed that my pressure was lower than normal and I had a small leak at the filter clamp. I ended up tightening the clamp as it was not fully tightened. We after getting as tight as I could by hand, the pressure was up to where I normally had it (16 vs. 12), but I still notice a very small leak. I'm guessing that I need to take the filter apart, make sure the O-ring is OK and put it back together. What should I be looking for to be sure all is OK?