My parents used to have a huge community tank filled with every variety of fish you could think of. My great-grandfather bred black bettas back during the Depression and we still have a tank that he used. It's about 20gal, a "bookshelf" tank, and quite nice! We kept our four male betta in there before they got wiped out by lymphocytosis.
We haven't used it in the last two years, but Mom's hinting that she'd like to give it to me at some point to divide.
When I got Octo, my parents would text me and ask me how their "grandbetta" was doing. :P Very adorable! They also love Hestia - they haven't met her yet, though.
My boyfriend's parents think I'm nuts, but are going to sell me their two 55-60 gallon tanks that came with the house that they bought a couple of summers ago. I plan on starting a community in one and a sorority in the other. Both are going to be planted. The "in-laws" (haha - not married yet!) have no idea!