Goldfish in General,
Goldfish Behavior 2,
Goldfish Behavior 3,
Goldfish Systems, &
FAQs on Goldfish System: Tanks (Size,
Quality (Algae, Smell, Cloudiness...
Nitrate, Nitrogen Cycling),
Betta & Goldfish (Keeping) by
Judy Helfrich (in the CA Accidental Aquarist
Goldfish 101: The Top Ten
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:
What is a goldfish?
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!
And variety there is! Fantails, Ryukins, Lionheads, Veiltails…
sport mutations abound in terms of body shape, finnage, eye shape and
Some examples of goldfish
A Bubble Eyed variety
A Telescope Eyed variety
A Pearl Scale variety
A Lionhead variety
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.
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
Filter and aeration choices
include in-tank, outside canister and
hang-on power models.
Do goldfish need a heater? What temperature (range) should
goldfish be kept at?
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
What should I feed my goldfish and how often?
Like all Minnows, Goldfish lack teeth on their jaws; using pharyngeal
teeth instead to grind largely algae and plants as food.
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
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:
What pH water should I use w/ my goldfish?
moderately alkaline pH is best; 7.2-7.6; easily measured and adjusted.
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.
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
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.