Learn about the general fish care and the harmful organisms that constantly surrounds fish pond

Well-nourished fish in a well-managed pool have strong natural resistance to potentially harmful organisms that constantly surround them.

Feeding:

Floating pellets are best for koi carp as any excess uneaten food can be removed after a few minutes.

  • By mid-April fish can generally accept food everyday the water being over 10C (50F) .

  • Light feeding morning and evening is better than one heavy feed.

  • Remove uneaten food after 10 minutes.

  • Good quality fish food is essential in maintaining the health of the fish and the pond. For koi carp this is an ever-developing science and encompasses a seasonal regime that demands more detail, better explained in koi specialist books.

Fish problems

Most pathogens of fish are found either on the fish or in the pool environment in small numbers. In good conditions the immune system of the fish is in fact increased by their presence as a kind of natural vaccination caused by their intrusion.

With the conditions in the pond not being ideal i.e. water low quality, combined with other stressful factors, the organisms that are normally kept at bay are given the opportunity to thrive. For instance, after a long winter with little opportunity to digest food at low temperatures, the fish are no longer resilient to parasite, bacterial, fungal or viral activity, which is revived at much lower temperatures than the fish immune system. In fact as the temperature of the fish world warms up, in the early stages their immune system struggles to keep in control. Then when a sudden unexpected cold snap occurs we might find a sudden spiral of pathogen population taking advantage of a faltering immune system. Koi Carp in particular might suddenly succumb to Septicaemia or Ulcer disease.

Procedure for diagnosing and treating fish problems

1. Identify and deal with the cause of distress.

a. Check water quality. If you cant test it yourself, get a local aquatic centre to help.

b. Note when you first noticed the problem.

c. Is it just one or all of the fish infected and are the symptoms getting worse?

d. Make a note of the symptoms.

These observations are essential if you find it necessary to call in expert help or if the disease has occurred since the purchase and introduction of some new fish.

2. Improve water quality.

3. Diagnose and treat the disease. If it is an individual fish with a disease, this may mean removing the fish from its environment (ideally to an aquarium) particularly if other fish are breeding. This will also prevent harassment from other fish.

In this way you now have the opportunity to ensure that the patient receives high quality food - little and often and with no fat. But do not feed during treatment unless it is just salt treatment.

It will also be easier to treat the disease directly by SWABS, DIPS or BATHS. You can control the fluid balance by giving a salt treatment of 3 grams to a litre of water. Removal to an aquarium will be less stressful all round rather than the persistent removal from the pond environment.

Treatment

WARNINGS: 1. DO NOT USE ANY PROPRIETARY TREATMENT CONTAINING FORMALIN OR POTASSIUM PERMANGANATE WITH ANY SALT.

2. SOME FISH DISEASES CAN INFECT HUMANS. USE RUBBERGLOVES OR PLASTIC BAGS WHEN HANDLING DISEASED FISH AND DISINFECT NETS AFTERWARDS.

3. HANDLE POISONOUS CHEMICALS WITH CARE. IF THEY ARE POISONOUS TO PARASITES OR BACTERIA THEN THEY ARE LIABLE TO BE POISONOUS AT CERTAIN TOXICITIES TO FISH AND TO YOU.

4. MANY CHEMICALS CAN AFFECT THE PERFORMANCE OF YOUR BIOLOGICAL FILTER SYSTEM. Some will stop it functioning biologically immediately.

General points of treatment

Most fish problems can be effectively treated with proprietary treatments from the shelves of most aquatic centres.

1. Read instructions carefully.

2. Treatment in a pond? Do not introduce fish to a recently dosed pond and do not add new water during treatment.

3. Refrain from feeding prior to any treatment.

4. Dose correctly. If the patient is "hospitalised" in a tank of measurable size then correct dosage is easy. The effect can be seen. The chemical is not wasted.

Vol. in Litres = (length x width x depth) in cm

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1000

Vol. in gallons = (length x width x depth) in feet

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6.25

Hospitalisation (removal of the fish to a quarantine tank) might be necessary if you propose to use organophosphate chemicals since these are poisonous to orfe and rudd and the dosage for other fish needs to be very accurate.

5. If you do treat the fish in a hospital tank or pond, aeration may be necessary to ensure a satisfactory level of oxygen for the fish as many treatments reduce the oxygen level in water. Since a lot of medication seems to be more effective if administered at night, this is doubly important as oxygen levels drop at night. Bear this in mind even for pond treatments.