Hot Spring Tri-x Filter In Caldera Palatino?

[passmaster16]

I wanted to buy an extra filter for my Caldera Palatino so that I have a spare while I'm cleaning the other filter.  My Palatino came stock with a standard 65 sq feet paper filter, watkins pn 71827 (stamped 31114 on bottom) measuring 10.5"x8.5" with 3" inner diameter.  Would the Hot Spring Tri-x filter work in this tub?  It appears that the inner and outer diameter is smaller on the tri-x compared to the 71827 so I assume that it wouldn't.

[d00nut]

I can't remember if the stand-pipe is the same size on both those spas.  If I remember correctly, I believe they are because they both use the same style Nature 2.  I think it would work (going off the top of my head) but I have to ask why?  Just curious.