I've got an in-ground pool, and a DE filter from Jandy. The pressure gauge is in an assembly bolted to the top. The assembly looks like something like this (image from catalog, mine is pretty much ...
EDITED FOR TL;DR: I have an above-ground fiberglass spa in the backyard of my home. I'd call it a four-person as more than that would probably overflow the tub, but it's got seating for up to seven; ...