I have a Pentair FNS plus 48 DE filter. It has a small leak around the separation between the upper and lower tank. I replaced the large o-ring last year. Any ideas how to stop it. IIRC I had the same leak last year but it wasn't nearly as bad. It was very slow. Even now it just seeps out but it annoying. I don't want to buy another o-ring if it could be another problem. Also I installed the o-ring dry. I didn't use any teflon lube. I'm not sure if that's correct or not.
Thanks for the help,