Pond fish koi treatments

Every garden pond, even the smallest contains a living ecosystem. We can fall into the trap of regarding the water in a pond as playing an insignificant part in maintaining our fish in tip-top health. This misconception is all the more evident when confronted with sick or unhealthy fish. We readily reach for a chemical that will treat the fish, hoping to cure the problem.

But most fish health problems require a two-pronged approach, needing to confront the disease-causing organism (be they bacteria, fungi, parasites or viruses) in addition to identifying the cause of the disease and rectifying it. Sometimes this may well involve treating the pond, to improve the water quality so that once cured, the fish do not succumb to the same problem again.

A healthy pond produces healthy fish. By maintaining a healthy pond, our fish will thrive and we will enjoy a fishkeeping life free from disease and the need to regularly treat our fish.

Throughout our own lives, we are likely to require different courses of medication. Our health service will pay much attention in our early years to preventing disease (through inoculation and vaccination) and after the prime years of our life, are likely to require further medical attention more frequently as our bodies age, become tired and worn out. A pond’s life is very similar, where its life and health are likely to benefit greatly from a good deal of attention in its early stages making sure it starts off on a strong footing, with subsequent intervention required at a later date if required to maintain the health of a pond and its inhabitants.

What pond treatments are available to maintain a healthy pond, and should things go wrong, address fish health problems?

Such treatments can be divided into two groups.

Pond treatments

Fish treatments

Pond treatments: Creating and maintaining a healthy pond environment.

a. Tap water conditioner. The water companies that supply us with drinking water have a legal obligation to ensure that it is fit for human consumption. They do not however, have to ensure that it is suitable for fish. Chlorine and other chemicals are added at source as disinfectants, but unfortunately, chlorine is extremely irritating to the delicate gill tissue, causing fish stress and an increased susceptibility to disease. When filling a new pond with tapwater, or topping up after a partial water change, a tap water conditioner should be added to neutralise the toxic effects of chlorine. Many tapwater conditioners will bind up toxic heavy metals and many also contain soothing colloidal additives that coat and protect delicate exposed fish tissues from irritants that may be introduced via tapwater.

b. The second step in creating a healthy pond, that will sustain healthy fish is to establish a biofilter. A newly purchased filter will take several months to become fully established with colonies of beneficial bacteria that will breakdown the toxic waste excreted by fish into less toxic by-products. A filter can be left for bacteria to colonise naturally, taking a long time to do so. This vital process can be accelerated by adding bacterial filter start additives to a new pond and filter. This will mean that more fish can be added sooner, in the confidence that bacteria will be breaking down fish waste immediately. Although bacterial filter starts speed up the colonising process for a filter, care should still be taken when introducing new fish to ensure that the bacteria in the filter can keep pace with the rate of ammonia released by fish. Testing your water for ammonia and nitrite will verify this.

c. Probably the most common complaint of new pond owners is when their crystal clear pond is plagued with nuisance algae. Green water (pea soup) can be cleared using a UVc, in line with your filter, blanketweed however, is a different story. Pond treatments for blanketweed will include either algicides that actually kill algae or other less direct algae inhibiting chemicals. Such pond treatments can remove the nutrients that cause algae to thrive (nitrates and phosphates) or add a dye to the water to starve the blanketweed of light, thus controlling its growth.

2. Fish treatments.

By providing your fish with a stable and healthy environment, they will respond positively by growing and displaying vibrant colours. However, there are times when disease may strike for no apparent reason or through accidents such as overfeeding, pump failures or even introducing unhealthy stock. Once diagnosed, any diseases should be treated rapidly.

Some of the most common ailments experienced by pond fish include:

* Whitespot. Fish look as though they have been dusted with granulated sugar. Affected fish may also gasp or ‘hang’ at the surface. * Fungus. Cotton-wool-like growth on body or fins. * Finrot. Ragged tail and fins, caused by bacteria that erode fin tissue. * Parasites. Irritation caused by microscopic parasites on gills or skin will result in fish flashing or scratching in the pond.

Standard, ‘off-the shelf’ treatments are available for all of the above diseases, which involves treating the pond water (rather than the fish) causing the disease organisms to die. It is essential that before adding any medication, to prevent overdosing, that you know the volume of your pond. In addition, extra aeration should be added to the pond during any period of medication.

We treat, but the fish heal themselves

The act of dosing a pond against a disease is only the first part of the treatment process. The successful recovery of a diseased fish relies on an effective chemical treatment working in partnership with good water quality and a complete and balanced diet. We thereby provide a supportive environment in which the treated fish can heal and recover.

Prevention or cure?

A useful strategy in the fight against disease is to treat a pond with a preventative dose of antibacterial or antiparasite treatment in spring and autumn. These are the periods when pond fish are most under threat and will mean that fish are less likely to undergo an attack from disease-causing organisms.

Many pondkeepers, through a combination of good management and good fortune never have to treat their ponds for disease. By focussing on providing a healthy pond and realistic stocking rates, it is possible to prevent problems from occurring rather than responding to them with chemical treatment. This should be the ultimate goal for every pond keeper.



Kill blanketweed and string algae.