Just wondering if the same 10 gallon rule applies to hex aquariums? Particularly as this would be easier to fit a larger aquarium in the same space.

I dont really like hex aquariums for goldfish. They have much less surface area than long tanks, and also the goldfish like to swim farther rather than higher. So in a hex I would say about 20 gallons per goldfish to be safe. Also make sure to have a bubbler or something in there to make sure they have enough oxygen. Hex tanks are great for tropicals but I would really recommend something longer for goldfish.

I agree with The post above me.

Thanks for the input, I have more experience with bowfront and rectangular aquariums which is why I asked.

hex tanks may be better for roundish fancy fish since they will have lots of room to turn. those fish swim slow and take lots of grith too. I probably should get a hex myself but those are quite expensive and all those corners kinda obstruct the view