Goldfish Care

The Goldfish, Carassius auratus is a freshwater fish, popular with beginner aquarium keepers as well as more advanced hobbyists. The Goldfish is available in a number of selectively bred varieties, with variances in body shape, size, colour, as well as finnage & eye shape.
The goldfish is generally considered a hardy species of fish, however some varieties are considerably more "tough" than others, and a reasonable rule is that the further removed from the original species body shape, the more delicate the fish, with Comet & Shubunkin varieties being the hardiest & varieties such as Blackmoors & Bubble Eyes being considered less hardy.

Goldfish can tolerate a wide range of temperatures; hardy pond fish will withstand winter temperatures dropping to near freezing allowing that the pond does not freeze solid, and NZ summer temperatures of up.to 28 Degrees Celsius (with adequate filtration & Aeration).
The optimum temperature range for Fancy Goldfish varieties is between 18-22 Degrees Celsius, however a range of 10-28 Degrees is acceptable as long as the temperature does not fluctuate too rapidly.

Water Conditions are as important for Goldfish as any other species of ornamental fish & it should not be overlooked that Goldfish can be quite heavy polluters, therefore filtration is a necessary & important consideration for any pond or aquarium.
Safe water parameters for Goldfish-
pH 7-8
kH 3-7
gH 6-16
Ammonia 0 mg/L
Nitrite 0 mg/L
Nitrate 0-20 mg/L

Water changes should be performed at least 30% fortnightly, the easiest way to perform a water change is with a gravel vacuum, which collects waste out of the gravel, syphoning off the dirty water, but leaving decor, equipment & fish safely in the tank. Replacement water can be from the tap, but should always be treated with a water conditioner such as Aquatan or Toxivec (Even roof & bore water should be treated).

Goldfish in aquariums should be fed daily with a quality Goldfish food, such as Sera Goldy or Sera Goldy Royal. Goldfish foods are specially formulated to meet the Goldfishes nutritional needs, higher quality foods contain less "Fillers" and Phosphates & cause less pollution in the tank, this means that water quality is easier to maintain & that algae may be slower to grow.
Pond Goldfish can be fed daily during late Spring & Summer, with less frequent feeding during the remainder of the year. Goldfish should not be fed if pond temperatures drop below 10 Degrees, as their metabolism slows down & food will not be properly digested. Pond foods such as Mix Royal and Bio Granulate provide balanced nutrition for pond fish.

Goldfish can grow quite large, and this is worth considering when choosing an aquarium or when buying fish for an existing aquarium. Our maximum recommended stocking capacity for Goldfish is 1 fish per 10Ltrs in a filtered aquarium, with possible re-evaluation as the fish grow. Comets & Shubunkins are not usually recommended for aquaria due to their potential size (Adult size- 1 fish per 50Ltrs), fancy varieties are considered much more suitable and can be kept in smaller tanks.

Goldfish often eat live plants, however this does not preclude them being kept together, choose hardy plant varieties & where possible allow the plants to become established in the pond or aquarium before adding the fish. Aquatic plants will require lighting & fertilisation to thrive.
Suitable aquarium tank mates for Goldfish include Bristle nose Catfish, hardy Corydoras species & Freshwater snails. Other tepid water fish species may also be kept with Goldfish, but size & temperament must be taken into account.

In conclusion, Goldfish make an excellent fish for the beginner aquarium keeper & are available in a range of unusual & beautiful varieties. However as with any pet, it is worth familiarising yourself with their needs & requirements, this way you will get to enjoy a cleaner, healthier aquatic environment and happier, healthier fish.