Looking after goldfish

Goldfish are one of the easiest and most popular species for beginners to keep. Avoid these common mistakes which novice aquarium keepers make:


Image result for sad goldfish in bowl

Mistake 1: Using a fishbowl.

Never keep goldfish in a bowl! Always use a proper fishtank.

In cartoons, movies, magazines, comics and other popular forms of media, goldfish are kept in bowls. This is because a bowl is a pleasing, round object to look at which doesn’t take up much space. Sadly, the bowl is an absolutely terrible way to keep goldfish.

Fact: Goldfish bowls are banned in Rome because they are considered to be inhumane!

The shape of fishbowls means that it is very hard to add cleaning accessories such as aquatic plants and filters. Because the opening of the fishbowl is smaller than its widest area, it can be very awkward to reach into the fishbowl and clean any algae that has grown with time.

Goldfish are also a species that grows very quickly.  A small tank will very quickly be overgrown – remember, it is a common fishkeeping misconception that fish will stop growing when they become too big for the tank! A fish will continue to grow forever, it does not automatically “detect” when it is growing to big for the tank, it will simply start suffering, therefore its crucial that your fishtank is large enough!

Mistake 2: Overcrowding.

Do not overcrowd your fishtank!

The best prevention for overcrowding is to have a large fishtank. Overcrowding causes many problems in your aquarium such as excess ammonia from waste produced by goldfish. Overcrowding may stress

Mistake 3: No cycling.

Goldfish produce large amounts of ammonia, make sure you cycle the tank!

Imagine someone constantly spraying bleach into your face throughout the day, not only is this unpleasant, it is extremely unhealthy and you would develop serious health problems and eventually die. This is the equivalent for goldfish when you fail to cycle your water with a suitable aquarium filter. Goldfish produce huge amounts of ammonia, the smaller the size of your aquarium tank, the faster the concentration of ammonia increases.

Mistake 4: Overfeeding.

I’m sure many of you may have made this mistake when you were a child – overfeeding your goldfish.

It is very fun and satisfying to feed your pet fish and watch them eat, however it is extremely easy to overfeed a goldfish. If your goldfish cannot eat all the food you give it within 3 minutes then it is being overfed. Goldfish prefer to eat food that is floating at the top or in the process of falling to the bottom, once the food has reached the bottom of the tank it is rarely eaten. Uneaten food will soften and decompose into a waste substance called “mulm”. Mulm is harmful to your aquarium environment because it promotes excessive algae growth and releases unhealthy amounts of chemicals into the environment.

Flake food or pellet food should be the main staple food for your goldfish. Occasionally, to keep up the variety, you can provide live food to your goldfish as a treat, examples include bloodworms and live brine shrimp. A good estimate for the amount of food a goldfish to handle – the volume the size of its eye. Another reason for removing uneaten food is to avoid confusion during the next feeding session to what has just been thrown into the tank vs what was left from the previous feeding session.

Mistake 5: Not changing the water regularly.

It is important to regularly change the water of your aquarium to remove excess chemicals, remove waste and introduce aeration.

Depending on the size of your fishtank, the water level needs to be changed at different frequencies. In a small tank (not recommended!) you may need to remove the fish from the tank with a scooper net and replace the entire fishtank.

For a larger aquarium, you may only need to replace around 25% of the water quantity in the fish tank once a month.

The best way to monitor the quality of your aquarium water to find the best frequency for replacing the water is to use a water condition monitor.

Mistake 6: Using untreated tap water to house fish

Many people use nothing more than tap water for their fish. Although some people get away with it because the tap water in their area is good enough for fish, this is a gamble that we don’t recommend taking.

Tap water contains chemicals such as fluoride and chlorine – good for humans to use and drink but not designed for fish to swim and live.

If you live in a very clean area, rainwater is a good substitute. Be careful though, rainwater is often polluted in major cities, and may even be acidic – this will be deadly for your fish.

Mistake 6: Cleaning filter equipment with tap water

Another post about tap water.

Avoid cleaning your filter equipment and aquarium substrate with tapwater. If your aquarium equipment isnt infected, has excess algae or clogged, you should avoid cleaning it. Aquarium equipment houses essential healthy bacteria which plays an important role in the functionality of your ecosystem. The beneficial bacteria is often very delicate and can easily be killed or removed by a strong stream of tap water. If you must clean your filter equipment, use a clean bucket or container to scoop some water from your aquarium and run it gently through what it is you want to clean.

Mistake 7: incorrect temperature

Goldfish are not tropical fish, they do not need very warm temperatures. The standard room temperature of 74F/23C is ideal for goldfish. A temperature that is too, around 60 F, 15C, goldfish will move around very slowly and stop eating. When temperatures are too high, higher than 80F or 27C, goldfish will also start moving very slowly and overheat.

To increase the heat of your water you can use a simple aquarium heater. To decrease the water temperature, you can use a fan to blow on the outside of the fishtank, float an ice pack at the top of the tank or even use a professional fish tank cooling system.

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