Related FAQs: Goldfish in General,  Goldfish Varieties, Goldfish Behavior, Goldfish Behavior 2, Goldfish Behavior 3, Goldfish Systems, & FAQs on Goldfish System: Tanks (Size, Shape...), Lighting/Tops, Decor, Gravel, Plantings, Heating/Temperature, Aeration/Circulation, Filtration, Water Quality (Algae, Smell, Cloudiness... Ammonia, Nitrite, Nitrate, Nitrogen Cycling), Maintenance, Trouble/Fixing, & Goldfish Compatibility, Goldfish Selection, Goldfish Feeding, Goldfish Disease, Related Articles:  Betta & Goldfish (Keeping) by Judy Helfrich (in the CA Accidental Aquarist series), Goldfish Systems, Goldfish Nutrition, Goldfish Disease, Minnow Fishes,  Goldfish 101: The Top Ten Goldfish Questions

By Robert Fenner & Tiffany Bromfield

 

 

In this age of “Top Tens” on television, magazine articles and more, here’s the pre-eminent questions regarding the venerable,
all-time aquatic pet; the Goldfish:

 

1)      What is a goldfish?

A.    Goldfish are minnows (of the family Cypriniidae); and like domestic dogs all varieties/sports of goldfishes are the same species (Carassius auratus). These are temperate water fish who grow to good size, particularly the sport called the Comet, which can get to past a foot in length, not counting the tail!

B.     And variety there is! Fantails, Ryukins, Lionheads, Veiltails… sport mutations abound in terms of body shape, finnage, eye shape and color.

 

Some examples of goldfish varieties
A Bubble Eyed variety	A Telescope Eyed variety
A Pearl Scale variety	A Lionhead variety

 

2)      Can I keep a goldfish in a bowl?
A. No; not for long at least. Goldfish need space; to move, breath, grow. Small specimens may be kept in containers of a few gallons, but they need filtration, aeration… or they will suffer, die.
B. Best to get a large enough tank that they can live in for a good long while, at least ten-fifteen gallons per specimen.

Goldfish need a good sized system; a real aquarium or pond to be happy and healthy. A tropical aquarium kit suits them well; with the heater set low to avoid drops in temperature.

3)      Do goldfish need a filter?
A. Yes; the most common cause of goldfish poor health and loss is exposure to accumulated waste; particularly ammonia. Goldfish need over-sized biological and mechanical filtration to keep their world viable.

Filter and aeration choices include in-tank, outside canister and hang-on power models.

4)      Do goldfish need a heater? What temperature (range) should goldfish be kept at?

A.     Much more important than any given temperature is that this doesn't vacillate; change a great deal over short periods of time. Better by far to have a heater here; and set it to about 65 F.

Though goldfish are cool to cold water animals, unless they’re living in a large tank or pond, they will suffer for lack of a heater due to too much temperature vacillation.

 

5)      What should I feed my goldfish and how often?

A.    Like all Minnows, Goldfish lack teeth on their jaws; using pharyngeal teeth instead to grind largely algae and plants as food.

B.     A good staple diet, especially pelleted, is all your goldfish need. Frozen and flake foods can be messy by comparison. Two small (about the size of the eye of your fish) feedings daily are good. Take care that no food remains uneaten after a few minutes.

Beware of re-packaged flake foods, and too high protein formulations

 

6)      What gets along w/ goldfish?
A. Other peaceful cool temperature, hard, alkaline water quality life. Bunch plants like Anacharis/Elodea, Hornwort, Parrot Feather/Myriophyllum, cool water snails, small minnow-like fishes like danios… are all great. Beware of Algae Eaters; as these will hurt your goldfish by sucking on them.

Goldfish are best kept with… other goldfish. Beware of sucker fishes like Plecostomus and “Chinese” Algae Eaters; these cause goldfish woe. Do consider placing some suitable plant material for looks, food, filtration. Shown: Anacharis

7)      What pH water should I use w/ my goldfish?

A.    A moderately alkaline pH is best; 7.2-7.6; easily measured and adjusted.

8)      How often should I change the water?
A. Once a week is a good time for gravel vacuuming and replacing about a quarter of the water. New water is best stored for the week ahead of use; not requiring treatment to remove sanitizer.

9)      Will my goldfish breed?
A. Not likely… they need to be mature; of good size; and in a good-sized system to reproduce; and of course have at least one fertile female and male.

10)   What should I do if my goldfish looks sick?
A. Review your system conditions first and foremost for environmental issues. Do a water change is almost always a good idea. IF you suspect pathogens, read on the Net Re.