Is a 20 gallon sustainable for a fantail?

[Aquaticbubblegum]

So I live with my parents and the biggest tank I can have  is a 20 gal tall (I have other smaller tanks) and I have a good sized fantail goldfish not adult size but still big. I was wondering can I keep him in that for another 2 years cause that’s when I’ll probably move out. Right now I have a big sponge filter with a big hygger duel sponge filter and an internal filter and I do 50% water changes once or twice a week. I love this fish and don’t want to get rid of it I just love goldfish.

Oh and I have plants 

[CJs Aquatics]

It sounds like you love this fish and he is well taken care of. That being said, you seem to be aware he eventually needs more space to grow and swim. You also seem to be aware of his needs and have a good plan of action for him. I think one of the biggest reasons people come up with the rules about tank size is less often about the amount of space or quality of water or requirements fish need to lead happy lives and more often then not to dissuade people who don’t have the fishes best interest at heart from taking them home or not properly taking care of them. Can he survive, yes, is he happy is the question? in this situation I think your doing everything in your power to meet that fishes needs, I see no reason to give it up as long as you stick to your plan, and continue to love and enjoy it and the hobby. 

[Flumpweesel]

If the fish has enough room to swim and you can keep the water good I think you can get 2 years out of this.

Do not over feed! He'll just grow faster. 

[AnimalNerd98]

I agree with the comments above. As long as the fish seems happy and you are providing good water quality and food, I see no reason to give up your fish. The conditions may be not ideal at the moment, but it is temporary. I would just keep an eye on the water parameters and bumping up water changes if there is ammonia or <50 ppm nitrates. You could add some rooted pothos or some floating plants to help with nitrates.
 

Also, I am a proponent of vacationing your fish outside during the summer months. If you have space in the backyard or something, you could let your fish vacation outside in a pond or large tub if you want to allow your fishy friend to stay in a larger enclosure, even if it’s only temporary. I know some people who vacation their goldfish outside in 30 gallon rubber maid trash cans 😂

[EVoyager31]

How much do your parents know about tanks? I feel like you could get a 40 breeder and tell them its a 20 long rather than a 20 tall 😂

If anything I would go for a 20L if you can, it has more surface area and would be better until you’re able to convince them to go a little bigger or move out.

Overall though I agree with comments above: Don’t overfeed, keep up with water changes and you should be OK with the 20T for now. 🙂

[Aquaticbubblegum]

Wow such amazing comments and help thank you all I will consider everything!

[StanF]

You can certainly keep one fantail goldfish in a twenty gallon tank for years. I've had these two guys in this 20 gallon tank for over two and a half years. The key is to monitor the water quality and change water often when needed. I like to do smaller water changes, so I generally do three or four 25% water changes a week.

I run the aquarium Co-op medium size Sponge Filter and intake filter. I use these two filters for my biological filtration . My HOB is filled with Pinky floss to catch the fine particles and polish the water.  Ammonia and nitrites are 0ppm, my nitrates run between 25 and 50 ppm (I have a well and my water is about 15 or 20 ppm right from the tap so I keep it as low as I reasonably can).  I feed them Repashy Super Gold gel food and frozen brine shrimp. 

StanF