One fancy goldfish can live quite comfortably in a 20-gallon tank. But if you’re still looking to give your fish away, you can try calling local pet stores (the smaller shops, rather than the large chains, may be more willing to accept new fish), Craigslist – even a close friend or family member. Sadly, I’m not familiar with many places to give away fish. If anyone else has first-hand experience, feel free to drop your suggestions. 🙂 You can also try asking your question on other goldfish forums (there’s a really good community over at Koko’s Goldfish – you can try your question there).

Hello Andre! Glad you found the website helpful. For common goldfish, I’d recommend only one or two in a 200-liter tank. These fish are really best suited in an outdoor pond though. If you’re just starting out, you should consider the fancy varieties – black moors, fantails, and ryukins are excellent choices because they’re so hardy. You can fit about 3 to 5 fancy goldfish in 200 liters of water comfortably, but I’d suggest starting off small – don’t get too many fish at once until your aquarium is more established. And before buying any new fish, set up your aquarium a few weeks in advanced so the nitrogen cycle has time to run its course. If you have any other questions, don’t hesitate to ask! I really hope you enjoy the goldfish hobby! 🙂

That’s so awesome, Sandra! My local pet shop was having the very same sale actually. Sadly, I wasn’t able to pick up another aquarium for myself. But I’m sure your goldfish are going to really like their new home. 🙂 They all sound beautiful – especially the ranchu! I love it when goldfish are so young – they’re always so curious and fun! Plus, you get to watch them grow. It’s amazing how big goldfish can get in a couple months!

Hi Hannah,

I wouldn’t recommend a 17-liter tank for a fancy goldfish. If your fantail is still young, you might get a couple months out of it, but eventually you’ll want to purchase at least a 76-liter aquarium (or 20 gallon tank). Your goldfish may even do fine in a 38 or 58-liter tank (10 or 15 gallons) if you simply don’t have the space for a larger aquarium right now, as long as you stay on top of water changes and water testing. Make sure you also have a good filtration system (I personally use power filters in my tanks, but canister filters are also very good). If your filter needs the extra help, you can even attach a sponge filter to the glass – these filters are really good at biological filtration.

Keep ammonia and nitrite levels at 0ppm (parts per million) and nitrate below 40ppm and your goldfish will be fine. You can read more about this in my water parameter guide. If you’re finding it tough to maintain zero ammonia and nitrite in the aquarium – even with a good filter and routine water changes – you’ll need to start looking at larger aquariums.

In a small tank, you may need to perform water changes more frequently than you would a larger aquarium. So if ammonia or nitrite is getting out of hand, try changing 25% of the water twice or three times per week. If that doesn’t help, change 50% of the water twice or three times per week until you can afford a roomier home for your goldfish. Make sure that all water going in is around the same temperature and pH as the water already in the aquarium – particularly if you’re doing large water changes! You don’t want to shock your goldfish.

Hope that helps!

Hi Kayla,

How many gallons or liters does your fish bowl hold? Your betta will likely survive just fine – betta fish don’t need as many gallons as goldfish do. And they usually don’t mind the smaller surface area.

Just don’t forget to test the water every week or every two weeks for ammonia, nitrite, and nitrate (this is how you know that your water is healthy for your fish!). You can read more about water testing here).

But if you do plan on getting more betta fish, don’t put two males in the same tank. They’ll fight!

Hope I answered your question – but let me know if you need more help!

Hi Kyle,

While not ideal, a 20-gallon tank may be okay as long as you’re very committed to maintaining good water quality. Make sure to test the aquarium water regularly to ensure ammonia, nitrite, and nitrate levels don’t get out of hand. Ammonia and nitrite should both always be at 0ppm (parts per million) in an established tank. Nitrate should be kept below 40ppm.

Because it is a little more work maintaining an overcrowded tank, I recommend having something like Ammo Lock on hand in case there are any sudden ammonia spikes. Ammo Lock will not remove the ammonia, but it will make the ammonia less toxic for your goldfish until you can reduce ammonia levels again.

On top of that, you’ll want to set up a powerful filtration system, since your tank is a little overcrowded. I highly suggest a power filter and sponge filter combo. A canister filter may be better if you didn’t want to go with a power filter. Whatever external filter you use, make sure it at least has a flow rate of around 200 gph (gallons per hour). More is fine too, as long as the water flow isn’t too harsh for the type of goldfish you’re keeping (your goldfish can still swim fine in the current).

As long as those water parameters don’t get out of hand, you should be fine. But if you can’t keep up with the ammonia or nitrite buildup, I’d suggest either increasing water change frequency or buying a bigger tank.