: This is an plastic adaptor into a water filter head. It was suppllied in a "kit" along with directions to use about 20" of tape which was supplied..Its a 3/4" plastic pipe thread into a plastic(rainfresh filter)head. Thanks for any help

Dee,
Some heads made from plastic are hard to seal.
Does the head come with a rubber washer?
If it does, I would only use the washer.
If no washer, then you will need to use the tape.
Many of my repairs involve removing excess tape from joints.