340 gallon aquarium, how many comet goldfish?

[raquelrv 0]

Hello!
I am building this indoor pond/aquarium in my living room, and it will have 230cm x 70cm x 80cm  (or 91'' x 28'' x 31'').
My question is, as full grown adults, how many shubunkin and comet goldfish can I comfortably put in this tank? I wanted to put 6 comets in it, is that reasonable?
Right now I have 2 shubunkin and 2 comet babies (6cm or so) in an outdoor mini pond, 80 gallons (310 litres). They will be moved to the indoor tank, but i wanted to get two more.
Thank you!

Edited January 5 by raquelrv
cm to inches

[shakaho 6,308]

Please read our Guidelines for Healthy Goldfish: https://www.kokosgoldfish.invisionzone.com/topic/121320-kokos-goldfish-forum-guidelines-for-healthy-goldfish/ You will find that we recommend 20 gallons per goldfish provided that you have adequate filtration and water change schedule. You might consider decreasing the height of your indoor pond. Goldfish do much better in shallow water.

[raquelrv 0]

Oh, it's just that I have read that for single tail goldfish it should be more than 20 gallons, some people say 40, other people say even 75 gallons for each comet goldfish so that's why I decided to ask.

[shakaho 6,308]

Our guidelines cover that.  You read a lot of total nonsense on the internet.   

[raquelrv 0]

Thank you! It's so hard to find reliable information 😆 I will make the pond more shallow!

[shakaho 6,308]

An alternative guideline says provide 2 square feet of surface area per goldfish.  People with large ponds often use this standard.  We recommend the 40B aquarium for two goldfish since it provides 20 gallons per goldfish AND more than 4 square feet of surface area.

[ABB63 38]

I have 1 common and 1 shabunkin in an 80 gallon reef tank. I chose the reef tank because it’s only 16 inches tall. It’s 24 inches deep  Front to back and 5 feet long. I can reach my arm down and wash the bottom and the backside of the tank because it’s only 16 inches. And they love the 24” x 5’ to swim back-and-forth.