The "one inch per gallon" rule

[Ocean Railroader]

How many gallons of water would this fictional freshwater alien race of mine called the Aqua need if they were kept as pet fish in a large tank? The Aqua would eat almost all duck weed and underwater plants in rivers and lakes.

Is there away to calculate fish tank volume requirements for fictional animals?

The Aqua in this artwork is four and half feet long and 180 pounds while the tail of the Aqua is five to seven feet long.

 

[Kaptain Kirk]

So I am not hating on this person. I have seen him produce some really nice fish. He clearly has a lot of fish in the tank. They do not specifically look too stressed though. Do you think fish could learn to even like these conditions? That is if the person is doing large water changes and feeding properly.(large daily water changes)

 

[Addi_13]

Thank you, I learned something new. I was always confused about this topic.

 

[Kayte]

So I know everyone will roll there eyes. Know that I did search this thread and didn't find the answer to my question. Given the 1 cubic inch to one gallon rule, how many adult fancy goldfish can I stock in a 250 gallon tank. I am starting up a new tank. What is the width and height of a ryukin, butterfly, lionhead, ranchu and oranda when they reach their average growth?

Keightley

 

[Oddball]

It's always sensible to gauge the number of fish for a tank by the size they'll likely attain in that aquarium. I don't want to specify any particular number for your 250. But, here's something I hope will help you decide.

 

[Kayte]

That is an atypical oranda! LOL Here are the average sizes of the different types of goldfish:

Oranda 8"
Ryukin 7"
Bubble-Eye 7"
Telescope 7"
Ranchu 7"
Lionhead 8"
Pearlscale 7"
Shubunkin 18-24"
Comet 18-24"
Koi 36-48"

Now some are more sleek and others are more round. So although I have a pretty good idea of length, I don't know about width and height of an average goldfish that I will be keeping: oranda, lionhead, ranchu, and telescope butterfly.

 

[itrebebag99]

My rule of thumb is judgement. If the tank seems too crowded it probably is. Better to be understocked than over.

Lol, that "one inch per gallon rule always confused me", as it seems to suggest that 20 3/4-inch neon tetras has the same bioload, and space requirements as a single 15 inch cichlid.

 

[The Rookie]

Finally I understand that rule. Ty

 

[crayfishlobster]

Would u put a 30 inch Asian arowana in a 30 gallon tank. NOPE. Whoever believes this is an idiot.

 

[itrebebag99]

Would u put a 30 inch Asian arowana in a 30 gallon tank. NOPE. Whoever believes this is an idiot.

Your strawmaning him. An 30" asian arowana must be at least 5 or so inches tall, and a couple of inches wide, therefore the asian arowana has about 300 square inches. Not saying I follow this rule, just pointing this out.