Well I had a large betta barracks system made up over Christmas and I've only just gotten around to filling it up.
The hardest part was finding somewhere to put it, and customising a spraybar to fit in each section.
It's a decent size, giving each betta roughly 4x12x12 inches, or 2.5 gallons each. At the moment it is only set-up with some hornwort and azolla as nutrient sponges and with the females I had to move out of my now torn down sorority.
The spray bar is experimental but it seems to be evenly circulating heat. I also intend on putting a small sponge filter in each section to help with circulation and biological filtration.
The water is only cloudy because of the ADA aquasoil being disturbed. Still thinking of just kicking that out and running it bare-bottom.