After writing about them since the beginning of this blog a year ago, it’s about time for an official fancy goldfish caresheet. These fish are the victim of many fishkeeping myths – they cannot actually live in fish bowls, they don’t actually have a short livespan and fish flakes aren’t a fantastic idea either – so it’s time to smash those!
Keep reading if you’re interested in buying a fancy goldfish or if you want to know how to better care for your fish.
|Minimum tank size||20 gallons (75 L), long, per fish|
|Temperature||62-71 °F (17-22 °C)|
|Length||Up to 10″/25 cm|
Carassius auratus, fancy goldfish, fancies
None, fancy goldfish are not found in the wild. Their wild ancestor, the Prussian Carp, is mainly found in Asia.
Fancy goldfish are available in countless shapes and forms, but the different varieties have a few things in common. They are rounder than common goldfish and have double tails, that are usually long and flowy.
Fancies come in all colors and patterns – regular orange is most common, but more exotic color varieties like panda, chocolate and lavender can also be found. What fancy goldfish are most loved for, though, are the interesting appearances that have resulted from selective breeding.
Big, bulging eyes, brain-like tissue on the head, enlarged nasal bouquets, dorsalless fish, nothing is too crazy. Subtypes range from quite similar to common goldfish to very extreme. For more information about fancy goldfish varieties, check out this article.
Determining the gender of your goldfish can be quite a challenge, but it is possible. Males will often grow small white bumps on their pectoral fins and operculum; these are called breeding stars or breeding tubercles.
Fancy goldfish requirements may surprise some fishkeepers – they have a reputation for being ‘beginner fish’ that can live in small tanks or bowls, which is unfortunately not true. Why goldfish bowls should be banned contains a more thorough explanation of why bowls are actually not suitable at all.
Fancies require about 20 gallons (75 l) per fish, frequent water changes and very heavy filtration. This is necessary because they are grow very big and produce a lot of waste – in smaller tanks, ammonia levels will get out of control very quickly, which results in health problems and stunted growth. A rectangular aquarium is preferable, as it allows for more oxygen to enter the water.
As for filtration, an external filter with room for biological filter material is the best idea – try to go for a filter rated for at least twice the size of the tank. I used an Eheim Classic for my 60 gal (240L) goldfish tank, which works fantastically when paired with a powerful internal filter. You can find a review of the Classic 250 here.
Good filtration will help keep the water values under control, but water changes are still necessary. Change at least 50-60% a week if you’ve followed the “20 gallons/75L per fish”-rule.
Because most fancy goldfish are quite clumsy, it’s a good idea to avoid sharp rocks and decorations. Sturdy plants like Java fern are a better idea. Goldfish will try to eat most plant species, but this one will almost always be left alone. If substrate is used (I personally prefer not to), go for sand instead of rocks or gravel.
Goldfish love digging around the substrate and gravel can get stuck in their mouth, which can cause suffocation! Sand is also much easier to keep clean, especially if you use a thin layer of filter sand. Play sand should never be used, as it rots easily due to the forming of anaerobic pockets.
Goldfish are very social animals that should never be kept alone for extended periods of time. Being alone makes them feel unsafe and vulnerable, which can cause unnecessary stress, so go for at least two goldfish.
As for other tankmates, there aren’t many options here, unfortunately. Many people keep their fancy goldfish with tropical fish like guppies and mollies or subtropical fish like danios, but I personally don’t recommend this as the tankmates may either be eaten or one of the fish will suffer due to the difference in temperature requirements (goldfish should never be kept in tropical aquariums). Fancy goldfish and their single tailed cousins are also usually not a good combo, as single tails are much faster and may outcompete the fancies for food.
The only tankmates I’d recommend are snails like ramshorn or Nerite snails. These often do a great job at algae eating and won’t be bothered too much by the curious goldfish.
Time to smash another goldfish myth here! Though not all flake food is bad, the cheap “goldfish flakes” that can be bought at any pet store are not actually good for your goldie – they don’t contain the nutrients it needs.
For a healthy goldfish it’s a better idea to go for a varied diet consisting of a staple pellet (I feed Hikari Staple), blanched veggies like zucchini, peas and kale, and frozen/live foods like bloodworms, brine shrimp or mosquito larvae. It’s also possible to make your own goldfish gel food.
Divide the food in small portions throughout the day. I aim to feed my goldfish at least 3-4 times every day – pellets once or twice a day and veggies and frozen foods the other times. If one of your goldfish outcompetes the others when it comes to food, try feeding in different places at once or feeding floating and sinking foods at the same time so they all have a fair chance.
Fancy goldfish are endlessly fun to watch due to their behaviour and personalities. They’re curious, silly, clumsy and very enthusiastic – once they get used to someone regularly feeding them, they will start begging for food whenever anyone enters the room.
Silly as it may sound to some, many goldfish keepers feel a real ‘bond’ with their goldfish that can’t be achieved with most tropical community fish. Fancies all seem to have their own personalities, which makes them perfect for anyone who is a bit bored of regular community aquariums.
Goldfish are usually friendly and peaceful towards each other and like to stick together and follow each other around most of the time. During spawning time more ‘rough’ behaviour may occur: males will start chasing the female around in an attempt to force the eggs out. This can get a bit ugly especially if you have more males than females. Keep a close eye on them and temporarily separate the female if she seems too stressed.
Breeding fancy goldfish is quite a challenge, and although it can be very interesting, it’s not something to be taken lightly. If you want to breed your fancies, be prepared for endless water changes and possibly having to cull deformed/sick fry.
Once the fish spawn, usually on stem plants like anacharis or on spawning mops, the eggs should be removed as quickly as possible (or they will be eaten before they can hatch). A small barebottom aquarium with a (small) air pump and a heater set to ~76-78 °F/24-25 °C is a good place to keep them until the fry are big enough to be moved to a bigger tank. Be sure to check on the eggs regularly and remove ones with fungus on them to prevent it from spreading.
Newly hatched fry have a yolk sac they can feed on for the first 1-2 days; don’t disturb them during this phase and don’t start feeding yet, as this will foul the water. When the yolk sacs have been absorbed, you can start feeding. A special fry food is easiest, as the fry are too small to eat most other foods. Keep the water in the fry tank level low (4-5 inches/10-13 cm) until the fry stop clinging to the bottom/sides all the time. This helps them develop their swim bladders more easily.
After the first week you can start doing water changes (at least 100% a day) and increasing the amount of food; feeding 5-6 times a day is necessary to ensure the fry grow well. Newly hatched brine shrimp or ground brine shrimp usually work best in this stage. You can also start picking out the fry that are obviously deformed or sick; look for bent spines, fungus or missing parts. It may be hard to cull these deformed baby fish, but they will suffer and eventually die if you don’t.
After a few weeks it’s time to switch the fry to a bigger, filtered tank or Sterilite tub. Clean the filter daily and continue doing daily water changes; cull any fry that seem deformed (look at the mouth as well) or that show unusual behaviour like bottom sitting or floating.
Breeding fancy goldfish is something to take seriously! If you’re not sure, don’t try it.
If you have any more questions about fancy goldfish or if you think I forgot to mention something in this caresheet, don’t hesitate to leave a comment below!
Other goldfish-related articles on Aquariadise: