Goldfish care fact sheet
Goldfish make great pets and with regular feeding and tank maintenance they can live for over 10 years. Under good conditions in a large tank some varieties can grow to 30 cm.
- Goldfish are coldwater fish and do best at 18 to 23° Celsius and a pH of about 7.2 (water that is very slightly alkaline).
- Fish tanks are preferable to goldfish bowls as they have a larger surface area for gas exchange and allow more room to swim. Pick a tank that is appropriate for the size of your goldfish. Don’t overstock. You are better off with 1 or 2 healthy fish than 3 or 4 unhealthy ones.
- Place your tank in a stable area away from fresh breezes (which can cause the temperature to change quickly), loud noises, vibrations, and direct sunlight (this can cause algae problems and overheating during summer). Try not to tap on the glass as this may frighten your goldfish.
- Fish tank cycling. It is always best to allow your tank to cycle before you fully stock your tank. The means that the nitrogen cycle in which good bacteria break down harmful waste (mainly ammonia and nitrites) from fish and uneaten food is working properly and is stable. It can take several weeks to cycle a fish tank but you can speed up the process using a product such as Stress Zyme or Cycle which contains millions of good bacteria. Always understock a newly cycled tank and it is a good idea to do more frequent water changes (see below) until the good bacteria are working well and is stable. There are plenty of good articles on the internet on how to cycle a fishtank.
- Filtration. Goldfish produce a lot of waste so it is useful to provide a filter, particularly if you have a few goldfish or one or two larger goldfish. Clean your filter twice a month.
- Aeration. Goldfish use a lot of oxygen from the water. If your goldfish is gulping for air at the surface you probably don’t have enough oxygen in your tank. A good filter should provide enough aeration but you may want to add a small airpump and an airstone.
- Decorations. Use only aquarium safe decorations and choose ones that don’t have sharp edges or places they can’t get stuck in. Some decorations such as driftwood, coral and shells can make the tank more acidic or alkaline.
- Substrate. Many people like to have gravel in their tank. Gravel harbours good bacteria and looks great, however, it also provides areas for left-over food and fish waste to build up. Clean your gravel weekly with a gravel vac. Goldfish will suck food of the bottom when feeding and are also likely to suck in gravel. Make sure the gravel has no sharp edges and choose gravel that is large enough that your goldfish can’t get it stuck in its mouths.
- Lighting. In a well lit room lighting is probably not necessary. However if you are keeping plants in the tank or want to see your fish more clearly then you may want to add a light.
- Plants. Coldwater plants can look great in your tank but goldfish like eating many types. While this is great for the goldfish you may want to consider plastic plants.
Never use flyspray or other aerosols near your fish tank. These have compounds that can kill your fish.
- Use good quality goldfish food. Goldfish like a variety of foods so you can supplement their diet with blanched veggies such as lettuce (Cos is the best for feeding) and zucchini/courgette and frozen foods such as brine shrimp and bloodworms.
- Feed once or twice per day and never more than your goldfish can eat within 3-5 minutes
- Remove excess food as it will foul the water and can lead to further problems.
- If want to keep healthy goldfish water changes are essential. This helps keep toxins such as ammonia and nitrates at acceptable levels and replaces minerals. Change 10% of the water weekly in a filtered (and cycled) aquarium, and 25% in a non-filtered aquarium.
- Use a water conditioner when making water changes. Water conditioners neutralise and detoxify harmful substances from your tap water such as chlorine/chloramines and heavy metals.
- Never change most or all of the water in a tank. An established cycled tank has thousands of good bacteria that help break down toxins.
- Never use distilled or demineralized water as fish needs minerals to be healthy.
- If your tap water looks cloudy then your local water provider may have flushed the system with chlorine.
PH - Goldfish thrive at the 7.2 - 7.6 range and though they are able to withstand variations in pH much better than other fish an effort should be made to maintain their water in this 7.2 - 7.6 range.A sudden change in pH is detrimental to your fish, and continued exposure to high or low pH is likewise harmful.
If you have problems contact your local pet store or FNZAS aquarium club . If you take a water sample from your tank into most pet shops they will test it for pH, ammonia, and/or nitrites, and provide advice. There is also plenty of good information and advice on the internet.
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