1) What are major challenges facing fish ponds as spring approaches and pond water warms up?

During colder weather when koi become lethargic, their immune system is weakened. As the weather warms up again, it is important to build up their immune system. As water temperatures rise, beneficial bacteria in their bodies might not pick up fast enough to cope with pathogenic microbes - bacteria and fungi - that are inevitably present in the water.

Fluctuations in water temperatures in early spring can cause problems. With a few mild days, the fish can become more active but then, during a subsequent cold spell, they become less active again. These activity changes can cause problems.

The effectiveness oThe effectiveness of the filter has also been reduced in the winter. Therefore, it is important to ensure that the bacteria in the filter also pick up and multiply again. A filter boost product might be applied, eg Viresco Filter-Start.

2) What stress can the fish in the pond have suffered during the winter months?

Poor nutrition during the cold weather leads to a weakening of the immune system. This opens up the possibility of the koi succumbing more readily to disease. There is also a tendency for koi to pick up wounds that are caused by self-inflicted pressure at the bottom of ponds. Wounds can also be caused from the resting process.

3) When should you start feeding fish in the pond and also how much. Is any special food required?ate autumn,During late autumn, winter and early spring, if koi are at all active, then it makes sense to give them food. Feed with a wheatgerm product. Even very small amounts of food, eg one or two pellets, will be beneficial as there will be less chance of infections arising in the gut.

As the fish become more active, stick with wheatgerm based food until the water temperatures rise.

4) What illnesses are pond fish prone to as the water gets warmer? What signs should worry mer?

Even healthy koi carry some parasites, but these do not necessarily become a problem. However, when fish are stressed and have with a lowered immune system then the parasites can take over. Perhaps the main ones, as the water warms up, are body flukes (gyrodactylus) and trichodina.

The flukes themselves are not a direct problem but the wounds they cause can become sites for secondary infections. These bacterial and fungal infections can become killers. They replicate on fish with low immune systems, on fish in water that is of poor quality and on fish living in conditions of overstocking. na is perhaps the most important parasite. It lives on all fish but it is only when it gets out of control that it causes problems. Certain conditions are conducive to rapid reproduction of these parasites and this is when serious problems can arise. Overstocked ponds, ammonia and nitrite contamination and generally poor pond conditions all can cause an increase in the incidence of trichodina. It shows itself as a white film that is usually first noticed on the head.

5) Why is aeromonous a threat, and what can be done to minimize this threat? Aeromonas and Pseudomonas are bacterial organisms that are found in most ponds around the world. They need not be a problem to koi but if their numbers get out of hand, they become pathogenic and cause disease. These microbes cause ulcers and various forms of rot - fin rot, mouth rot and tail rot. If left untreated, the fish will eventually die. Koi naturally have some defence against these problems. One is the production of a slime coat and the other is their immune system. The stronger the immune system, the more likely the fish is to suppress the pathogens.

Many koi die from these ulcer diseases in spring. Why?

It is known that the production of the slime coat is affected negatively as the nitrate level in the water increases. It is therefore advisable to minimise the nitrate content. This can be done by putting into the pond one of the microbial Viresco products. These products are sold primarily for the suppression of blanketweed and other algae by removing their nitrate food source.

However, the microbes contained in the Viresco products will also compete with bacterial and fungal micro-organisms that are present in ponds and prevent these microbes from becoming pathogenic. See prices and buy online at the Viresco UK store

This is why Viresco is recommended to be introduced during the winter so that the microbes it contains can outcompete the aeromonas and pseudomonas bacteria when the water temperature start to rise.

6) Can 'vitamins' be given your pond fish to boost immunity?

Yes there are vitamin supplements that can be fed to koi. However, some of these may contain, for example, copper and iron in amounts that should not be used. Another way of introducing vitamins to fish is to give them more "natural" foods such as peas, lettuce, oranges, spinach, prawns etc, from which the relevant vitamins will be extracted.

Viresco (UK) Ltd is bringing in 2007 out a mixture of a microbial product with humic acid that can be mixed as a paste to be added to food. The microbes in the mixture will out compete potentially pathogenic bacteria in the intestine, thus reducing the probability of infection. At the same time the microbes in the product will improve the digestion of food, thus reducing the amount of waste. The humic acid is a product that will improve the immune system. It is a natural product that contains a range of micronutrients. It has also been shown to have anti-viral properties so its potential for koi health could be very significant in the future because of on-going viral problems such as KHV.

7)What is best way to prepare for spring?

it is important to keep the environment in which the koi are living as clean as possible. This means that water quality should be monitored and controlled. There is a tendency for koi keepers to think, because very little fish activity has occurred during the winter period, then little action is required to improve the enviromental conditions in which they live. Water changes also can be made having checked the water parameters. 8) Can pond cleaning actually release dangerous organismas and bacteria into the fish pond? If so, how do you do it safely? Use Viresco Aqua or Viresco Koi to prepare for warmer water when blanketweed and algae can become a problem.

Yes, this can happen. Isolate filters and drain them. The filter media should be removed where practical and cleaned of any particulate matter. Wash through the filter media, ideally with pond water. Do not use tap water that might be chlorinated.

Using a vacuum will remove waste matter that might be settled on the bottom of a pond.

9) What is the biggest error pond keepers make when getting their fish ready for warmer weather?

Perhaps the biggest mistake people make is to introduce too much food, too fast without checking the water parameters

See prices and buy online at the Viresco UK store