What size tank for comet/common goldfish?

Hello,
I have two common or comet goldfish (I'm not sure) that are almost 6 in long (growing quickly) in a 20 Gallon tank. These fish are very active and I can tell they need more room- they are bumping into everything. The nitrates are also really bad, like over 60ppm, despite weekly 70% water changes. I need to get them a larger tank and the Aqueon 75 gallon looked good to me. The Goldfish Tank website said "30 gallons for one common or comet goldfish, with at least 15 gallons per additional fish" Since I am expecting these fish too reach at least 10 inches long, a 45 gallon tank is not adequate in length and width. So here's my question: is the 75 gal a correct size for my future, two adult (10-12 in) goldfish? Or will they not have enough space? I want the new tank to be a final purchase- something they will not outgrow and can life the rest of their lives in. Also, how long can they be kept in the 20 gal without getting stunted? If anyone has a suggestion on tank size, that would be great! Thanks!

 

They are already too large for your 20 gallon. The info on that site doesn't seem right to me. Common goldfish and Oscars grow to about the same size as adults and 75 gallons is the smallest recommended tank size for one of them. I feel you need at least 120 gallons for 2 commons to grow large and live long lives.

 

A pond would be even better for them. If you can't provide a very large tank or a pond, you should consider rehoming them to someone with a pond.

 

If you can getting a tank that is 100 gallons will be best. A 75 is the minimum for only 1 goldfish!!! Here is a link for goldfish: . Not all websites are accurate when it comes to fish keeping. Even though some sites are focusing on that fish sometimes they still aren't the best.

 

I think that is the best article I've ever seen about goldfish. I'm saving it for future reference

 

Ahhh yes! You should also read the other articles that they have! Such as keeping goldfish in planted tanks, other types of big fish, etc. Also make sure that in any goldfish thread that you are in please spread the link!!! Before this site I never even knew that fancy goldfish gets to 12 inches!!! I only though the comet and common goldfish get that big.

 

yeah, that first picture on the article is amazing, with the baby fancy in a bowl and then the bowl compared to it's parents. That is such a good way to show why a bowl is no where big enough. Also, a goldfish as big as a cat!!

I'll make sure to spread the article It's a shame that Fishlore isn't one of their suggested forums though. I've found this forum to be the best and most consistent in terms of advice given.

 

That is because the site is in UK!!! They might not find this site popular since it is mainly U.S although you do see other people from other countries on here.

 

I'm from the UK myself I don't think it really matters what country the forum is in because at the end of the day good fishkeeping is good fishkeeping. Only a problem when certain products or shops are suggested I guess.

Sorry, we've gone off topic. Goldfish should be in massive tanks

 

Ok, thanks everyone. The Aqueon 125 gal has 18 in width, is that enough for a 12 in fish to turn around? Otherwise the Aqueon 180 is two feet wide and six feet long so they should be fine in that. Water changes in a 180 gallon tank scare me though.

 

That my friend is the problem with many beginners. Sometimes when people get fish they put themselves first before the fishes needs. Many people are like oh a big tank will be a lot of work to clean, yes but it is better for the fish. A 180 gallon is perfect, and I suggest you get it. Goldfish when truly taken care of properly are hard work. Too many people see them as beginner pets mainly since they are sold for a cheap price and bred in the millions!

 

Good on you LoicS for wanting to do best for your goldfish I'd definitely go for the 180g if I were you. Think how amazing your fish will look in there!

 

I did do my research before buying these fish and have had them for almost a year now. I bought the 20 gallon because I was not sure if I was going to permanently keep them or give them to someone else. However what I found before said that 50-60 gallons was fine for adult fish. I didn't mean to sound cruel because I love my fish and I will do the water changes even in a large tank. I was planning on buying the python water changer, so any advice on that? I will need to use tank water to water plants outside so I was wondering how fast it could drain a 180 gallon and especially if it could be connected to a garden hose. My parents are going to be shocked about the tank size and due to the drought here in California we can't waste any water. Also, once again, how much turning room does a 12 in fish need?

 

Sorry not sure about this since I don't have big tanks! However goldfish are really beautiful when they are in big tanks. You will have more time to admire them then to always be stress of cleaning the tank and seeing them in a small tank!

 

Goldfish can get bigger than 12". I would go with at least a 24" wide tank personally.