The ambient temperature affects not only koi carps, but also beneficial microorganisms and bacteria in filtration systems. Therefore, control over the quality of the water in the pond is vital. It is necessary to carry out constant checks on the level of ammonia and nitrite in order to be as sure as possible that the quality of the water corresponds to what is necessary for the life of koi.
Koi is a thermophilic fish. For complete well-being, they need a temperature of approximately 18-25 ° C. Therefore, during the summer, the metabolism of koi changes, coming to an optimal value, and the immune system becomes as effective as possible.
pH factor. Check the level of acid-base balance, even if your pond is built of concrete and cement, as rainwater entering a body of water can cause an increase in pH.
Zippers. Unpredictable spring weather can bring a different kind of problem. Recently, an explanation has been proposed as to why fish in some ponds ended up with broken spines after a thunderstorm. A lightning bolt that struck near a reservoir can cause a strong electric field and strong muscle cramps if it enters the water, which in turn can lead to a fracture of the spinal column in the fish.
Flowering water. The two main factors that distinguish summer from winter are: firstly, higher average temperatures, and secondly, a greater amount of light. These factors are central to the normal growth and development of koi carps.
Blooming water can be a problem, and not only from an aesthetic point of view. Certain types of algae, such as chlorella, can produce toxins when propagated. Multiple death of such algae can cause serious oxygen starvation in the reservoir, filling it with decaying organic matter. Large artificial ponds can also suffer from a lack of oxygen, especially at night, when plants living in ponds cannot release oxygen through photosynthesis.
Koi is able to survive in water with insufficient oxygen content, capturing air from the surface, but in any case, this situation is very unfavorable and difficult for the fish. At night, not only plants produce oxygen, but carbon dioxide is also released into the water as a product of the respiratory activity of fish. The dioxide is highly soluble in water, and forms carbonic acid. During the day, plants, by photosynthesis, take dioxide and even bicarbonate ions from the water, which in turn cause an increase in pH, reaching a peak shortly before sunset.
Ponds with overwhelming plant growth can experience severe fluctuations in pH. By night, the pH reaches its maximum value; in the morning it drops by plants absorbing ions and carbon dioxide by photosynthesis.
Ponds with excessive flowering of water become subsequently super-saturated with oxygen, during the day. In this case, the fish will show signs of decompression sickness.
Control measures: all problems associated with algae can be avoided by installing ultraviolet lamps and increasing the aeration of the pond. Increased aeration will help to avoid oversaturation with oxygen, which can lead to gas embolism of fish.
Herbicides and pesticides - All of these components are toxic to fish, so it is not recommended to place them near a reservoir. For example, a gust of wind can move particles of chemicals toward your body of water or chemicals can enter a body of water with rainwater. Poisoned insects can also get to the surface of the water.
Medicines. Formalin, a common component of ectoparasitic drugs, reduces the oxygen content in water and is toxic to gill tissues. By reducing the oxygen concentration in warm water, this substance can cause various problems.
Control measures: always check the oxygen content in the water, especially if formaldehyde containing preparations are used.
Translation from English: Zooclub portal
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Overpopulation in a pond is not dangerous
The danger of overpopulation of a reservoir depends on the experience of the owner. If the fish eats, retains bright colors, and there are no symptoms of the disease, this does not mean a good condition of the reservoir. With an excess of fish, there may be such a level of ammonia and nitrite, which still kills slowly. Most of the health problems in fish in domestic ponds are due to poor water quality and improper maintenance, and not the appearance of bacteria or parasites. If there are too many fish in the pond, and there are no skills for an extremely high fish landing, problems will appear sooner or later.
Playful koi carps jumping for joy
Fish can rub against each other, against the walls or bottom of a reservoir, or even jump out of it. Sometimes fish jump out of a pond due to fright, but everything is fine with water. But usually, these symptoms indicate problems with water quality or infection with parasites. If several fish are behaving suspiciously, you need to understand the reason. Watch the fish carefully and try to interpret their behavior correctly.
Need to turn off equipment for the winter
Depends on how cold the winter is. And some equipment, such as an aerator, can never be turned off. At the depth of many freshwater reservoirs in winter is the heaviest and warmest part of the water, usually + 4̊C. In shallow, domestic reservoirs, wind is enough for water to circulate from below. The fountain significantly cools the water. After stopping feeding, do not forget to clean the filter, especially if you turn it off during frost. The aerator is left to work in the winter, however it should not be aeration from the bottom fence. Connect the aeration stone and lift it closer to the surface. During severe frosts, you need to turn off the pumps of fountains and streams so that freezing water does not drain the pond.
It is necessary to periodically process koi carp from parasites
Treating fish when it’s not necessary, or improperly selected treatment, is another common problem. Fish are randomly processed during quarantine, causing stress and increasing susceptibility to pathogens. The pond is treated against parasites and the population of beneficial bacteria is killed. With rare exceptions, most hazardous microorganisms are constantly present in open water. And to make sure that they are not there, you can only sterile conditions. In the open air, this is impossible, and the destroyed microorganisms will quickly recover. Constant problems with parasites mean errors in the maintenance of fish, and treatment of a reservoir cannot be eliminated. Chemical exposure is the last treatment method and can only be used after accurate identification of the pathogen. Take care of the health of the fish, and they will take care of themselves.
Water in a pond with koi carps needs to be salted
If koi preferred salt water, they would live in sea bays and climb into rivers for breeding, as salmon or sturgeon do. One of the features of the life of aquatic vertebrates is the need to maintain a constant composition of fluids. Freshwater fish tissues contain more salts than the environment. From the environment in the water through the gills and intestines, water constantly moves, which carps secrete through the kidneys. Salts return to the tissue before excess moisture leaves the body.
Carps are freshwater fish that are not adapted to a high salt concentration, in which there is more salt in the water than the body. In this case, the reverse movement occurs - the liquid leaves the body and tends to a more saline environment. This is the basis for treatment with salt baths for parasites within 3-5 minutes - some microorganisms lose water and die. Water with a low salt concentration (0.5-0.6%) in terms of salt composition is less different from koi liquids than fresh. Due to this, the fish spends less effort to maintain a constant composition of fluids. This method is used for 10-15 days for weakened fish, and then gradually the water is returned to the fresh water parameters. Carps do not need to live in salt water constantly; they live in fresh water.
All wounds on the body of koi carps are mechanical damage
Koi can accidentally lose their scales or even damage the fin, especially during spawning. But not all redness, wounds and torn fins are caused by mechanical damage to sharp objects. Often they are caused by a bacterial infection, which in the early stages is easy to cure. If such a “wound” is left to heal and not interfere, it will only expand and deepen. Since the wound is an open place for osmosis and diffusion between the environment and fish, koi with skin damage can be kept in a weak salt solution until the wound is healed. Also, salt provokes the secretion of mucus, which protects the fish from the penetration of parasites. It is easier for pathogenic microorganisms to enter fish tissue through an open area of the skin.
When treating the pond with drugs, you need to turn off the filter
Supporters of turning off filters say that drugs will destroy the beneficial bacteria involved in the nitrogen cycle. Some drugs actually inhibit nitrifying bacteria or even kill them. Not all drugs work this way, and often you can find a replacement for a drug that inhibits the biofilter. What to do if replacements cannot be found? After all, if the filter is turned off before the introduction of drugs, pathogenic microorganisms, especially parasites in the form of cysts, can remain in it. And when the biofilter is turned on during treatment, the death of a large number of bacteria can increase the concentration of toxic ammonia, which is undesirable for already weakened fish. If you need to use drugs that inhibit the biofilter, it is most reliable to clean the filter before adding drugs and leave it turned on after. Microorganisms in the water column, as well as in direct contact with water, will die from the drug. Since not all bacteria in the bacterial film will come into contact with the medicine, they will soon be able to restore the population.
You need to wait before releasing koi carps into the pond
You can’t immediately launch a lot of fish into a freshly filled pond, because due to the lack of bacteria that process ammonia and nitrite, a high level of these dangerous substances is inevitable. But if you leave the pond as is and do nothing, the waiting time will be in vain. A few weeks before the fish start, you need to turn on the filter and throw small portions of food into the water. Ready-made starter bacteria cultures for ponds are also useful. Processing ammonia, the most dangerous substance, bacteria multiply to the right amount within 4-6 weeks. But this does not mean that all fish released earlier than this deadline will inevitably die. First, let out a few small and not very valuable fish, carefully feed them and monitor their condition. Large water changes in the new pond do not need to be done.
Before releasing koi carps, you need to bathe in a solution of drugs
Improper treatment is more dangerous for koi than no treatment at all. If you purchase fish from a trusted dealer, and especially if you do not have enough quarantine options, it is best to release koi immediately in a shared pond. Medicines must be able to apply, including carefully observing the dosage. Too large a dose or stay of fish in water with medicines longer than necessary, at least, will create additional stress, and can cause irreparable damage. During quarantine, fish are monitored and treatment is carried out only as problems arise. Accidental use of drugs, when the problem is not clear, is also unacceptable.
In winter, koi carps are at the bottom because it is warmer there
The body temperature of koi depends on the temperature of the water in which they live. In winter, when the water becomes cold, they are at the bottom, practically not moving, and thus conserving energy. In natural deep bodies of water, the effect of a thermocline arises - a layer of water with a temperature different from other layers. Fresh water has a maximum density at a temperature of + 4̊C. Therefore, if on the surface of a pond the water temperature drops to 0̊C and freezes, at the bottom it may be quite sufficient for wintering temperatures. In shallow ponds, water is constantly mixed and this phenomenon does not happen.
The more powerful the filtration, the better the water quality.
Water quality depends on filtration efficiency, and not on power. For a pond with a volume of 2-5 thousand liters, it is not difficult to establish filtering of the entire volume within an hour. However, powerful mechanical filtration does not mean that the water parameters will become optimal. Pumping the entire volume for 2-4 hours should be enough. If high ammonia and nitrite levels remain, increasing the filtration rate will not help.
Koi carp cannot be kept with plants
Carps are omnivorous fish that can eat plants. But if you understand the behavior of carps and get to know their habits more closely, you can save plants in a pond with koi. There are several ways to do this. You can cover the roots with rough stones, in which carps do not like to dig. Or place the plants in tall narrow containers or raise their edges above the water. The more plants in the water, the higher the chances that carps will not destroy them. It is advisable to include plant foods in the fish diet: lettuce, cabbage, green peas, etc. Carps prefer animal feed, and the habit of digging the ground allows them to find insects in worms and larvae. It is imperative to feed the fish well, otherwise they will have nothing left but to eat accessible plants.
My “natural” pond doesn't need equipment
Indeed, in nature, carps live without equipment. But in domestic ponds, the technique works precisely for the purpose of resembling a mountain lake, and not a puddle with the smell of rotten eggs. At home ponds, equipment is required. It is unlikely that your koi live in a huge muddy pond with an earthen or clay bottom, where they feed on worms and mollusks. If this is a small domestic pond, 1000 liters of water or so falls on one adult fish - the system cannot cope without equipment. Although a pond without equipment will last for some time, one day such an experiment in keeping fish can end in disaster. And most likely this will happen in the summer, when the water has the least oxygen and organic residues quickly decompose. Do not want to install equipment, you can make a pond for plants and a pair of purebred goldfish. Just do not try to plant small koi there - they grow too fast. All equipment is necessary only to make the environment most suitable for the koi.