I found my old 2000s era hexagonal tank. It's the Aqua Tech Hex 5. The filter and light were shit so I removed the lid and ordered a better ones on Amazon. These are its dimensions:

Height: ~12 inches (30.5 cm)
Width (flat side to flat side): ~11.2 inches (28.5 cm)
Width (point to point across the widest diagonal): ~12.75 inches (32.4 cm)
Width of each face: ~6 inches (15.2 cm)

Since its too small for any schooling fish, I decided to turn it into a dedicated planted shrimp tank with a couple of Amanos and tons of Orange Neocaridinas.

>Substrate
I bought some inert black sand

>Filter
NICREW Slim Aquarium Filter. I'll customize the filter media with a 30 PPI sponge and filter floss.

>Light
NICREW Clip on Aquarium Light with Red, Blue, and White LEDs

>Heater
YukiHalu Small Submersible Aquarium Heater 50 Watts

>Plants
I'm thinking to just use Pearl Weed and Moss

>Aquascape
I'll use a decently sized piece of lava rock in the center, and have some branching driftwood surround it from the top


Thoughts?