How many goldfish in a 20 gallon tank?

[S2000]

Just purchased a 20 gallon tank for my mother, this is her first tank and she's interested in keeping goldfish.

How many fish should she plan on keeping?

 

[jpappy789]

Zero, in the long run.

Personally, I believe in 30 gallon minimum for one fancy goldfish. Maybe more experienced people will disagree though...

 

[cellodaisy]

I have heard 20 gallons per fancy goldfish as a rule of thumb from several people, so that would seem to indicate that you could keep one. I have never kept goldies, though, so I hope one of our resident goldfish experts chimes in.

 

[Avi]

Keeping goldfish "properly" is one of the most difficult things in fishkeeping, IMO. One of the reasons is that there is such variety in color and type...and personality...that it's hard to have the self-control to maintain them within the proper limitation of numbers that make for good goldfish keeping. I'd say, honestly that two is the number that your Mom should keep. If she gets them small, I'd even go as far as to say three. They will grow, of course, and they may get too big so that you have to remove one...or maybe even two. But, from having kept fancy goldfish for many years, I can say that if there isn't any over-feeding and over-filter like crazy...you'd be able to have three in the tank for a good amount of time without any problem. Just be prepared for the possibility...the likelihood...that a bigger tank will be needed at some point.

 

[jpappy789]

Three 6-8" fish in a 20 gallon???

 

[reptileguy2727]

I generally go by the guide of 20 gallons for one and an additional 10 gallons per additional goldfish. HOWEVER, they are a schooling fish. Because of this they really shouldn't be kept in anything less than a group of six. So this really puts the minimum tank size for goldfish at 75 gallons. And that is only in reference to round-bodied goldfish, the long-bodied pond type goldfish need much larger, a school of six should have at least 125 gallons.

 

[McLendon]

You can keep two nicely in a 20gl but no more and I'd run a HOB filter rated for a 50gl tank along with a box filter for a 20gl as well

 

[Avi]

Good filter advice, IMO, from McLendon. The more filtration the better and two filters is better than one, so that you can change the medium in one when it's time without disturbing the other so that the biofilter keeps going, which is something goldfish need because of the amount of food that they are capable of consuming.

 

[svf]

And LOTS of water changes. LOTS.

 

[crimsonmoon]

(not my pics)




self explanatory
just be prepared for their maximum possible sizes