# Goldfish tank requirements



## FeelTheBern (Jan 13, 2016)

How big does a tank need to be to house a single goldfish?


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## magpie (Jan 3, 2009)

If you asked that question to 20 different goldfish owners you would probably get 20 different answers!

Personally I wouldn't like to see a fancy goldfish in anything less than 100 litres, or 150 litres for two. Single tailed goldfish tend to grow bigger than fancies, and with their streamlined bodies are a bit faster and more active... so for one of them I'd say no less than 200 litres.

Alternatively, a popular rule of thumb is 20 US gallons (76 litres) for the first fancy goldfish and 10-15 gallons (38-57 litres) for each subsequent fish, or 40 gallons (150 litres) for each single tailed goldfish.

I have 6 fancy goldfish in a 500 litre tank and I consider it fully stocked.


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## kittih (Jan 19, 2014)

I would say to some extent it depends on filtration. Generally it's not recommended to keep single tails in tanks as they should reach 10 - 12 inches if kept properly. Not only do they grow longer but also are quite broad fish so the waste they produce is huge. They also tend to eat any plants you put in so unlike most Tropical's you can't rely on the plants to absorb some of their nutrients.

My recommendation for a pair of single tails would be a 5 foot tank to start with with the plan to home them in an outdoor pond as they grow. Overfilter the tank with external filters).



With fancies who swim less strongly and grow less long in the body though can still grow to tennis ball size and above I would say ultimately a 4 foot or 5 foot tank for a pair / few at adult size. Again as they are messy fish it's wise to be over cautious and have excess filtration capacity.

If you are prepared to upgrade tanks regularly then you could start with a 3 footer for both types and upgrade when they need more room. That could be within a year though.


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## Fishyfins (Feb 28, 2009)

The general rule of thumb is 50L per fish for fancy goldies (moors, orandas etc...), starting with 100L as a minimum. So that means nothing less than 100L, but you could get 2 in there, then 150L for 3, 200L for 4 etc...
For standard goldies (comets, shubunkins etc...) this should be doubled or more. It is often not recommended to keep standard goldies in tanks at all due to their eventual size, and the mess they make.
Remember as well that goldfish are social animals, and often dont do well on their own. Usually 2 or more is beneficial.


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## magpie (Jan 3, 2009)

kittih said:


> If you are prepared to upgrade tanks regularly then you could start with a 3 footer for both types and upgrade when they need more room. *That could be within a year though*.


Yep, one of my 10 month old babies is nearly 6 inches nose to tail already and quite deep bodied too:


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## FeelTheBern (Jan 13, 2016)

Are there any coldwater fish that can be kept in a 10 gallon tank?


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## magpie (Jan 3, 2009)

FeelTheBern said:


> Are there any coldwater fish that can be kept in a 10 gallon tank?


Not that I can think of. Some people might suggest white cloud mountain minnows, but while they are quite small fish, in my experience they really appreciate a long tank and lots of swimming space.

10 gallons would be great for a single male betta, but they are tropical so you would need a heater.


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## FeelTheBern (Jan 13, 2016)

magpie said:


> Not that I can think of. Some people might suggest white cloud mountain minnows, but while they are quite small fish, in my experience they really appreciate a long tank and lots of swimming space.
> 
> 10 gallons would be great for a single male betta, but they are tropical so you would need a heater.


I've already got a tropical tank; I'd just like to try something different. What could I keep in a slightly larger tank?


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## NaomiM (Sep 22, 2012)

I have a temperate tank, so it has a heater in winter just to ensure it doesn't drop below 19 C or so, but it hardly ever comes on. There's lots of options for temperate - WCMMs, some barbs, some tetras, paradise fish, American flagfish, rainbow shiners, certain types of cory and pleco. Mine is 135L and all barbs at the moment as I found they're greedy little so-and-sos who didn't mix too well with anything else I tried, so I have odessa barbs and gold barbs at the moment. I might add a spotted bulldog pleco if I can source one.

You do have to watch what you put together, and 10G isn't very big, which does limit your options quite a lot. If you can go slightly larger, how about a single paradise fish, or even a pair if you get a big enough tank? You wouldn't need a heater for them either, so long as the room temp never drops between 16C or so.


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