Is it true that a 2 inches goldfish needs at least 25 gallons of water?

Question

in that case why do they sell smaller tanks in shops? i find it crazy to buy a 100 gallons tanks for 3-4 fishes!!!! even if they will gorw bigger.

Answer 1

It is crazy to buy a tank that big for goldfish. Two inch goldfish will only get to be about a foot long if taken care of properly. At that size, 3-4 fish would do fine in a 55 gallon tank. At 2 inches, they will be just fine in a 20 gallon tank for a year or so.

Hey tyrsodottir,
You are right about the oldest common goldfish! But check this out, the oldest Koi in the world died at age 226 year, yes 226, some years ago in Japan. I read that you can determine the age of a fish by the ridges on their scales (like rings on a tree). However, you must remove one to look at it under a microscope.

Answer 2

It's not true that you need that amount of space, however, the minumum reccomended space is one fish for every 8 uk gallons (36 litres) of water.

They sell such small tanks for one reason, and one reason only, the fact that the companies that make them are only in it for the money and not the fish's welfare.

Such small tanks cannot be filtered, and so, a build up of highly toxic ammonia starts in the tank. This effects the fish in several ways, the most obvious being that it destroys the gills. Having a fish in an unfiltered tank is pretty much the same as you being in a room that's being slowly filled with carbon dioxide.

Both fancy verietys and common verietys of goldfish can reach up to 12" (30 cm) in length given the right conditions and food. This is also why a large tank is needed. The miniumum tank size for a goldfish is 18"x12"x12". Anything smaller then this is just cruelty.

Answer 3

The RSPCA website recommends 4.5 litres (about a gallon) for every 2.5 cm (about an inch). Therefore, a two inch goldfish needs 2 gallons of water. Surface area is a more reliable method of determining how many fish your tank can take, the rule of thumb is one square foot per inch of goldfish. Bear in mind these measurements are based on having an adequate filtration system as well.

Remember that fish will grow, the RSPCA recommends that once they are 12cm in length they should be transfered to a pond.

Answer 4

Most common goldfish, believe it or not, can regulary attain a length of 10 inches (about 25 centimeters) and live for more than ten years (not sure about metric conversion on that one : P). The guideline that I hear the most is not one inch per gallon; nor 5 gallons per fish. The one inch per gallon rule can yield drastic results, such as one goldfish expected to have plenty of room in a ten gallon tank when really it would have trouble turning around in such a small tank, and 5 gallons a fish is even worse.

What I hear alot is 30 gallons for the first goldfish, and 10 gallons for each additional goldfish.

Answer 5

My guess would be that the recommendation has in mind the eventual full grown size of the goldfish, and I actually more commonly hear a rec of 30 gallons per goldfish.

This notion that "fish are fish" is shortsighted (to be kind). Different fish have different traits that have to be considered.
The example given, that bettas and goldfish are basicly the same, is actually a very good example of two kinds of fish that are very opposite from each other.

Bettas are aggressive, territorial, moderately active, cannot be kept with like kind except in special situations and tend to do best when kept solitary (as opposed to a community tank). They are relatively slender and don't produce a ton of waste. Bettas are tropical fish and need warm, softish waters. Bettas grow to 3 inches and live 2-3 years, sometimes as long as 5.

Conversely, goldfish are social, non-aggressive, reasonable active, do best in groups of their own kind and get along well with others. They are FAT and produce gross anounts of waste (which is the reason for the large amount of space they need), and they are cold water fish. Goldfish grow to 6-12 inches (depending on the type) and live 20 years or longer. The oldest known goldfish was "Tish" who lived in China. He lived to be 42 years old.

Personally, I would only keep goldfish in a pond and would allow a minimum of 5 gallons per inch for each, while I feel that a gallon is the reasonable minimum for a betta (tho I give mine at least 2 gallons).

Answer 6

No, you need a minimum of 5 gallons per fish, so 20 gallons for four.

Some of the 'novelty' tanks only hold around one gallon (four litres), so the fish could die; there isn't enough room for a filter in these small tanks.

Fish, even goldfish, need a filter and enough air surface to breathe.

Answer 7

Please don't listen to all these people who don't know anything about fish. Tyrsdotti is absolutely correct, fish are not fish, and true, even though a main concern is water quality, if you keep them in too small of a tank, it causes stress and is horrible for their health. Please take the time to google Goldfish, and you will find all your details somewhere, I would post them...but class awaits. Good Luck.

Answer 8

Ive just heard 10 gallons per goldfish, becasue that allows it to get pretty big without trouble

Answer 9

You can have as many fish as you like Untill it starts affecting the water quality. All depends on type of fish, type of filter,ect. If your water is fine add another fish, just keep a check on it. Good luck.

Answer 10

I understand that the average requirement is one (UK) gallon per inch of fish. But of course, that is calculated on their adult size, which might explain why you have been given that number.