Basic Guideline For Goldfish Care

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Cichlid Specialist
Original poster
Apr 27, 2006
New Mexico USA
Real Name
So you want to have Goldfish?

Goldfish are very common in home aquariums but a lot of times their proper care is very misunderstood. You have heard stories about keeping goldfish in bowls or keeping several goldfish in a small tank. In most cases the intention is good but usually leads to improper goldfish care.
That being said, there are a few misconceptions with keeping goldfish I will cover before going in to general care etc.

Goldfish are often kept in very small containers such as bowls or very small aquariums with no heaters or filtration. Goldfish need plenty of open swimming space and a bowl or small aquarium will not provide enough space. A lot of times this is can be the number one cause of death to your new goldfish. Goldfish such as Fantails can be kept in smaller aquariums because of their smaller rounder shape. That being said 20gallons should be minimum for one fantail and 10 gallons for each additional goldfish. Goldfish such as comets and other faster swimming torpedo shaped goldfish should be housed in much larger tanks 55 gallon being the smallest. In regards to the heater, although the goldfish is typically a coldwater fish, the common idea is that they can survive in the coldest of waters. While this is partially true, they can survive in colder waters, a heater is favored to stabilize the temp that they will be kept at. Stable water ensures better health of your fish. Goldfish such as fantails and fancies should be kept at temps between 65-75 degrees Fahrenheit. Goldfish such as comets should be kept in colder waters ranging from 50-68 degrees to be happy. Comet and other torpedo shaped goldfish will be much happier if a pond can be provided but can be housed in an aquarium for a long time. Goldfish can reach lengths of six inches to a foot depending on the type of goldfish, whether it is the torpedo shaped type such as comets or the round-bodied type such as fantails.
Proper filtration is also an essential Part in a successful goldfish aquarium. I would recommend you double up filtration on a goldfish tank meaning turn the volume of water over 10 plus times an hour and perform water changes of at least 50% weekly or sooner. Goldfish can be very messy and release a larger amount of hormones in to the water compared to other freshwater fish.

All types of goldfish cannot be kept with each other. It is true that the same species may thrive and some mixed also may, but some goldfish are slower and have different swimming habits. It is strongly recommended to separate goldfish with different swimming habits to reduce stress. Goldfish such as fantails and fancies etc. are some examples of slower moving goldfish and should not be kept with comets or faster swimming goldfish. If these types of goldfish are kept together it may lead to stress, as well as one type thriving and one type just surviving.
Adult size should be taken in to consideration when purchasing goldfish. Goldfish can live a very long time if housed properly some can live up to 30 years in fact. Fantails for instance have a lifespan of 10-30 years and like warmer temps whereas Comet type goldfish have a lifespan of 7-14 years and thrive at colder temps. Because of the size of these guys, goldfish produce more waste and will affect water quality much faster than your typical tropical aquarium fish. A 55 gallon should be the min tank size for a comet type goldfish although a larger longer tank would be better.

Some things to take in to consideration before getting goldfish is tank mates. Fish such as corys and plecos should really not be housed with goldfish because of the difference in temperature and diet. This will lead to one fish lacking the optimum environment and possibly a change in diet. Another thing to take into consideration is that goldfish can be very destructive in a planted aquarium. Goldfish will eat and tear up most aquarium plants with an exception of a few like Java ferns. It is advisable to keep them in tanks with fake plants and other decorations of your choice.

A common affliction of goldfish is problems with their swim bladder. The swim bladder is the part of the fish (inside) that allows the fish balance in the water. If you think swim bladder is the issue, the first method to try is to have the fish fast for 3 days, and then feed skinned peas. When you begin to feed normal food, do not feed a floating flake or pellet. Goldfish need to eat sinking foods due to their greedy gulping at the surface. As they greedily gulp at the surface during feeding times, often times they pull in too much air, thus causing this swim bladder issue. If all you have is floating foods, that will suffice but you must soak the food in tank water prior to introducing it into the tank for feeding. Be sure the food has absorbed enough water to make it sink once introduced.

Aquarium conditions should be as follows:
Ph: 6.5-7.5 and a KH of 4-20

Temp: 65-75 degrees Fahrenheit for fancy or fantails.
50-68 degrees for comet type goldfish although cooler temps can be tolerated.

Care level: Moderate

Max size: Round bodies: up to 6 inches Torpedo-shaped: up to 24 inches

These fish have a peaceful temperament and are omnivorous.

They are a member of the Cyprinidae family

Goldfish are originally from China but different varieties are bred world-wide now.

Other things that should be taken in to consideration for long term success for your goldfish aquarium should include:

Good water quality, regular water changes should be done to keep your fish healthy and happy. This is a must in order to ensure your goldfish will be happy and healthy.
A thermometer, this is essential to ensure the tanks temp is monitored regularly.
A heater as stated above, to keep a stable temp. Stable temps will ensure your goldfish wont be stressed due to fluctuating temps.
Good filtration also stated above, filters should be run 24-7. Filtration is extremely important for the health of the goldfish as well.
A test kit is an essential part of any aquarium I would recommend a Master test kit from Aquarium Pharmaceuticals. Water parameters should be checked on a regular basis to ensure that your water is stable.
A good water conditioner I recommend using Prime. Water conditioners Remove chlorine and chloramines from the water. Most conditioners also detoxify heavy metals and provide your fish with a natural slime coat.
A Gravel Vac There are several different gravel vac's on the market I personally use a Python for water changes but any will do the same job. Gravel vacs are essential mainly because a lot of the waste build falls to the gravel bed.
Lighting is also essential for goldfish as well as most all other fish 8-10 hours a day is a good guideline. The length of daylight each day, and the length of time aquarium lights are on, is called "photoperiod. A constant photo-period benefits almost all fish and invertebrates. The lights should turn on and go off at roughly the same time each day. Therefore a light timer is also recommended.

This article should be used as a basic guideline for keeping goldfish. There are many other types of goldfish out there and only some of the common types are mentioned in this article. Therefore if you are considering goldfish, research should be done on the specific type you are considering. By reading this article and researching specific types of goldfish you should be ready to achieve success with your new goldfish aquarium.
Happy fish keeping and good luck!!!!!!


Senior Member? Do I get a 5% disc.?
Good article. It's nice to see more and more goldfish care sheets talking 20G and 55G starting points, instead of the all-so-common 10G starting point... or worse. You should also mention that long-bodied goldfish do best in ponds since they are such big-time swimmers.

I think you should make that a separate paragraph so it stands out more and then repeat it in the aquarium conditions summary.

One other thing, I think the round-bodied goldfish should read "up to 8 inches" or "up to 6 to 8 inches"

Once again, very good article.
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