I have an FNS Plus (48) and need to replace the oring at the drain plug on the bottom of the filter. Its an 1.5" Oring. Two questions.
1. If I remove the drain plug will it be necessary to replace some DE?
2. Is that a standard replaceable part or would it be something proprietary to the filter? I don't want to take it off only to hear "I need to order that".