Navigation
Goldfish Keeping
Setting up your Aquarium
If goldfish are housed in rectangular aquariums that are properly constructed and maintained, they can live for many years.
If the aquarium is placed on the window sill, paint the outside surface of the glass which faces the window's light with a coat of green paint. This shelters the fish from the glare of sunlight and makes them show up better in the room. Also don't place the aquarium in a position where there's a risk of the tank overheating eg where the tank is subjected to full afternoon sun.
It's wise not to buy your fish until their new home is completely ready for them. The aquarium will require seasoning before the fish are placed in it. A layer of clean, small gravel should be laid on the bottom of the tank about 3 to 5cm thick. Ensure the sand or gravel you choose is not too light in colour, or your fish will not feel comfortable and exposed. Select some earthy tones like dark beige or brown in preference to white or dyed brightly coloured mixtures.
Water weeds such as cacomba, anacharis and vallisneria should be planted at the sides and back as these are chief suppliers of oxygen. When the weed has been planted in the sand, place a piece of brown paper over the plants and fill the tank with rain water.
Leave the tank unoccupied for the next few days. The water will appear dirty and opaque at first, but will gradually clear as sediments settle and an interaction is established between the plants and the organisms growing in the water. Never change the water entirely, but simply add new rainwater at intervals to make up for evaporation. For those without access to rainwater, there are now products available which dechlorinate and condition tap water so it may be used in aquariums without causing the fish harm.
Tank Temperature
Check if your aquarium is the correct temperature for your fish. The optimum is within the range of 14-20 degrees Celsius. At temperatures below 14 degrees Celsius, goldfish metabolism will slow down and they will move about less and not eat as much.
Goldfish cannot function in water below 10 degrees Celsius, and will remain still, hardly breathing, and will not eat. Temperature is VERY important to the wellbeing of your fish. If you live in a cold area and keep your aquarium in an unheated room in Winter, ensure the tank remains at between 16-21 degrees Celsius. Use a heater in the tank if it falls too low.
In Summer, higher water temperatures will result in your fish becoming more active. They will eat more food and use more oxygen to the extent that it is sometimes necessary to increase aeration of the tank, depending on the number of fish you have. Aerators are readily available from pet shops and aquarium supply stores.
Always remember that sudden changes of temperature can be fatal to goldfish, although they will withstand the transition from Winter cold to Summer heat if the change is gradual.
Oxygenating Your Tank
Fish that rest constantly on the surface of the water (apart from feeding times) are short of oxygen. Their water should be refreshed by bubbling air through it for a set period daily. Air pumps, with or without a charcoal filter, are beneficial if the aquarium is slightly overcrowded - a situation which should be avoided. Lack of oxygen means weeds are needed. In the correct quantities weeds alone can produce enough oxygen for the aquarium without the need for artificial oxygenation of water (provided there is no overcrowding). If a balance is established between fish and plants, the water should remain crystal clear and well oxygenated indefinitely.
Introducing New Fish
Once you have brought your fish home, which is usually in a plastic bag, open the bag to allow in fresh air, then reseal it again and float it on the surface of the water in the tank. It must stay floating in the tank for about 15 to 20 minutes so the water in the bag gradually reacches the same temperature as the water in the tank. This prevents the fish suffering from temperature-induced shock when they are transferred into the aquarium from the bag.
Feeding your Fish
Fish need to be fed, but DO NOT overfeed. Purchase a good quality food which has been specifically prepared for goldfish. Spread a pinch of food over the surface of the water 2-4 times a day (less in Winter) and the fish should finish this within 2 to 3 minutes. If too much is given, the water will become cloudy, polluted and bacterial levels will rise dramatically. Remember feeding changes with the temperature/activity levels, so as it gets cooler and activity decreases, feed less. When it gets warmer, feed more.
Cleaning
The layer of excreta which slowly spreads over the sand should be removed once or twice a week using a pipette or suction hose. Algae may sometimes have to be wiped from the glass surfaces with an aquarium scraper. This is all the attention a healthy aquarium needs, other than topping up with water at regular intervals to compensate for evaporation loss - monthly replacement of not more than two thirds of the tank of water if necessary. It is not advisable to change all of the water at one time, and better results may be achieved by using some of the commercial water conditioning treatments if you are experiencing water quality problems. If you have a filter, clean it weekly and replace the charcoal filter, but put a portion of the old charcoal back into the filter along with the new charcoal (to preserve nitrifying bacteria).
Snails are not generally necessary to keep an aquarium clean, and if introduced, their numbers should be kept low (about 5 or 6) as they can spread disease or may damage your aquarium plants. Snails eat algae and waste food, and a sudden population explosion of snails in an aquarium usually means you're overfeeding your fish, so cut back on food quantities.
Algae can be more effectively controlled by having scavenger, algae-eating fish sharing the aquarium. Blue green algae grows on the floor of the tank and on plant leaves particularly in alkaline water. It is a sign of unhealthy aquarium conditions. A commercial algae treatment (used strictly according to instructions), and more attention to water quality is required to correct this problem - seek specialist advice.
Green algae, which usually grows on the glass, is a sign of healthy water, and fish like to nibble it as a tasty snack. Remove it from the glass at the front of your tank so you can see your fish, but don't bother with removing it from the back glass. Excessive green algal is usually caused by too much light.
Brown coloured algae means that the aquarium is not receiving enough light.
Outside Ponds
Goldfish will do very well in outside ponds in most areas. However if you do live in an area likely to get sudden frosts or even snow, it is better to transfer your fish indoors during Winter. Place them in an aquarium or plastic tub, and be wary of metal containers as they may contain poisonous compounds such as zinc. If the container you choose is crowded, make sure that you aerate the water. Fish can be re-introduced to the pond when the weather warms.
Pond algae can be controlled by commercial remedies suitable for outdoor situations. If you haven't put an aerator in the pond, you will need suitable underwater plants to provide oxygen. These should be thinned and tidied up from time to time. Some surface floating plants should be added as they provide both shade and shelter for the fish. Be sure to keep them in check, and make certain they don't cover the entire surface of the pond completely, preventing sufficient oxygen uptake.
Ponds should be kept deep enough so the fish can escape predators such as cats. Ideally, there should be a rocky overhang around the sides of the pond as ponds with gradually sloping sides allow predators easy access to wade in, and provide no place for the fish to hide. Something protective and hollow inside with lots of openings through which fish can easily swim in and out if chased or threatened may also be placed in the centre of the pool.