What to feed

Good quality prepared fish foods provide a well balanced diet, however, fish do relish eating a variety of foods. Fantail goldfish in particular will benefit from a varied diet.

Daphnia, brine shrimp and bloodworm or a mixture are enjoyed by most fish and can be purchased either live, in frozen packets or in vitamin enriched jelly. Only buy live food from a reputable source, frozen foods should be defrosted before being fed.

Pellets or flakes?

Eating flakes requires the fish to spend a lot of time at the water surface increasing the amount of air which could be swallowed by the fish. It is mainly for this reason that pellets are thought to be better for goldfish, for whom swallowing air can contribute to swim bladder problems.

Treats?

Chunks of cucumber, courgette, blanched lettuce leaves and peeled peas are usually well received by goldfish and some tropical fish. Leave in the aquarium for 24-48 hours and take out before they go bad. Plant based fish foods, such as algae wafers, are also a good addition to the diet. All these foods should be in addition to a good quality fish pellet or flake.

How much food?

Fish, especially goldfish, are programmed to gobble  up everything they can, far more than they need in-fact. As a consequence it is very easy to overfeed fish.

Everything a fish eats is excreted into the water so the more the fish eats the higher the risk of pollution becomes. A well fed aquarium is more likely to develop poor water quality, sick fish and algae problems.

Gold fish and tropical fish have different nutritional requirements, use an appropriate food for each. Any food left in the aquarium after two minutes  should be removed.

Measure out food carefully, do not use a ‘pinch’. There are no exact rules for feeding fish but as a rough guide:

1-3 cm shoaling fish (minnows, danios etc)

3-4 tropical micro-pellets or 1-2 tropical flakes each per day.

2-5 cm goldfish

2-4 small pellets each per day.

5-10 cm goldfish

4-6 small pellets each per day.

Goldfish will keep looking for food even when they don’t need it.

Going on holiday?

If you will be away from your fish, it is important that someone checks the air pump is working and that if a fish dies it is removed from the aquarium straight away. Either of these situations could kill your fish before your return. A spare air pump should be left with instructions in case the existing pump fails.

Fish are live animals and so should be checked every day, even though they will probably not need feeding unless you are away for more than 10 days.

Holiday blocks of fish food can be used but there is a danger that if uneaten these foods could pollute the water. A well meaning but inexperienced feeder could do more harm than good by overfeeding fish while you are away. In most cases it is preferable to let the fish go hungry although certain fish may require more regular feeding.

If you do get someone to feed your fish measure out the correct amount of food and ask for this to be fed over the time that you are away.

What should I do if a fish dies?

If a fish dies you should remove it from the aquarium immediately, if left in the aquarium it will badly pollute the water. You should try to establish why the fish died. Make note of anything  which is abnormal. Take a sample of your aquarium water to a good aquatics retailer for testing and advice. It is often useful to try matching symptoms with pictures in a fish care book. 

Dealing with disease

Good aquarium husbandry and fish selection will help to prevent disease. Chronic stress can suppress the fish’s ability to fight disease, the most common causes are water quality problems.

If fish show symptoms of a disease get the water tested, if water quality is good then use a suitable medication to treat the fish. If water quality is poor this must be remedied before or at the same time as using medication. Make a note of all the abnormal symptoms your fish are showing and get advice on which medication to use.

Most medications include very clear instructions on diagnosis and treatment, some also offer a help line.

The carbon in the filter cartridge should be removed during the treatment period. Always follow the manufacturers instructions.

Swim bladder problems

The swim bladder is a gas filled sack inside most fish which controls their buoyancy in the water. Problems with the swim bladder cause fish difficulty in swimming, and is common with fantail goldfish. Bacteria infections and air swallowing are thought to be common causes of swim bladder problems. Feeding a varied diet can help in prevention.

Swim bladder problems are not usually life threatening, however it can be a symptom of a more serious disease. If a fish is suffering badly for more than a day or two it may be worth using a swim bladder medication.

Some fish suffer regular bouts of swim bladder; the fish is uncomfortable but soon recovers. If, however, a fish constantly suffers with swim bladder to the extent that it affects the quality of life, and nothing helps, you may wish to consider seeking advice from a vet.

Do fish need company?

It is unlikely that fish get lonely or bored, however, animals do benefit from having a more challenging lifestyle. Fish must be compatible with each other and goldfish should be of a similar size when introduced to each other.

Shoaling fishes like minnows need to live in a shoal. They can feel under threat of predation if they do not have the security of living in a group.

Water testing

Water tests should be routine for every fish keeper. You can purchase a test kit to use at home or take a sample along to a good aquatics shop. It is important to at least test for:

Ammonia

Ammonia (from fish waste) level is likely to be quite high every time a fish is added. Once the aquarium is established, ammonia readings should be zero.

Nitrite

Like ammonia the level is likely to be high when fish are added but once the aquarium is established should be zero. Subsequent high readings of ammonia or nitrite indicates that biological filtration has broken down or that the fish have been overfed.

Nitrate

Nitrate should be used as an indicator of your aquarium’s hygiene. It shouldn’t be more than 50 ppm above the level in your tap water. If it is higher then you should increase the frequency of your partial water changes.

pH

pH is the measure of acidity and alkalinity of the aquarium water. pH 7 is neutral, 1-7 is acid, 7-12 is alkaline. Most cold water fish prefer a pH of 7.5-8.0, tropical fish vary in their requirements. Even tiny changes in pH are very stressful to fish.