Ordered the PSI replacement gauge from the site. Received in good order. It's certainly more substantial than my OEM gauge. I have never taken apart my filter as I have a service open and close the pool. So my question is: do I truly only need a wrench and plumbers tape? Or is there a nut inside the top of the filter that I also have to consider? I'd hate to unscrew the existing and then learn I should have un-assembled the unit!
Thanks in advance.