FAQ Koi & Pond

Crucial are pond volume, existing stocking, filter performance, and the effect you want to have in the water. Large, calm Koi have a different effect than young developing Koi. In the Koi selection of Japan-Koi Wild you can filter by age, size, variety, gender, price, and breeder. If you are unsure, consulting before purchase is more sensible than a spontaneous wrong purchase.

There is no serious single number because stocking, final size, amount of food, oxygen, filter, and care work together. As a rough guideline: better fewer, but higher quality and with stable technology. If you are planning anew, the filter should not only suit the current stocking but also the Koi that will grow over the next few years.

Tosai are young Koi with development potential and usually a lower entry price. Nisai and Sansai often show body structure, pattern, and gender more clearly. Large Koi bring immediate presence to the pond but need space, stable water values, and appropriate filter performance. In the Koi selection you can directly set the age stages as a filter.

Kohaku, Sanke, Showa, Yamabuki, Chagoi, Karashigoi, or Soragoi are often good starting points because you can judge effect and development well. A calm single-colored Koi can visually soothe a group, a Showa or Sanke brings contrast. More important than the name is: The Koi must appear healthy, fit into the group, and come into its own in your pond.

Not automatically. Female Koi can develop more volume and presence, male Koi are often more elegant, color-intensive, and more interesting in price. For many ponds, a balanced mix is more sensible than purely chasing one gender. If gender is important, use the filter in the Koi selection and ask specifically about individual fish.

The breeder provides clues about origin, line, body structure, and development. That is why we display the breeder information clearly on the Koi. Nevertheless, the name alone does not decide: skin quality, body shape, movement, size, age, and condition must all fit together.

In the Koi Auction a selected lot is shown with image, data, duration, and current bid. You bid bindingly with your maximum bid. Only the next bid increment is visible. It is important to check beforehand whether the Koi fits the pond setup and how pickup or shipping is organized.

Yes, if the date, packaging, and acceptance are carefully planned. The Koi are packed in sturdy fish bags with water and oxygen and protected in special cardboard boxes. Details on costs, pickup, and binding appointment coordination can be found on the page Koi Shipping & Pickup.

If a quarantine option is available, it is professionally advisable. New Koi can stabilize after transport, temperature change, and transfer before joining the existing group. Without quarantine, the introduction should be done particularly calmly and the pond should be closely monitored in the following days.

Don't just compare color and price. Ask yourself: Which Koi complements the group, which size fits the pond setup, which character appears stronger in the water, and which fish is more realistic to keep long-term? If you name two specific Koi to us, we can help you via the consultation form to put the decision into perspective.

You should regularly check at least temperature, pH, KH, ammonium/ammonia, nitrite, nitrate, and oxygen. In case of problems, ammonia and nitrite are particularly critical. Individual values say little if not considered together. Therefore, measurements, stocking, feeding, and filtration should always be evaluated together.

Nitrite indicates that the biological filtration has not yet fully accomplished the breakdown or has been disrupted. Common causes are new filters, too much food, too dense stocking, too little biology, or a disturbed bacterial culture. Then: reduce feeding, increase oxygen, check water, and find the cause.

Regular partial water changes help reduce dissolved loads and stabilize minerals. The amount depends on the pond, stocking, food, filter, and tap water. Scheduled, moderate changes are better than rare emergency actions. Check temperature and water parameters to avoid additional stress.

Green water is usually caused by suspended algae. Sufficient UVC performance, appropriate flow rate, stable filter biology, less nutrient surplus, and a realistic feeding amount often help. UVC devices and suitable technology can be found in the UV-C & Ozone at Japan Koi Shop.

The amount of food depends on temperature, size, activity, season, water parameters, and filter performance. Koi should eat the food quickly; leftovers burden the water and filter. With Akita Koi Food and the feed calculator, you can better estimate the amount instead of feeding by feel alone.

With stable warm water and good filter performance, a high-quality staple food can be fed more generously. Digestibility, protein quality, energy, minerals, and the response of water parameters are important. Akita Superfood 2.0 is the direct feed range from Japan-Koi Wild and fits many well-maintained Koi ponds as a high-quality staple food.

During transitional periods, digestion is slower and the filter biology is often not fully active. Feed more cautiously, monitor temperature and water parameters, and only increase the amount when the Koi are active and the system remains stable. When in doubt, feed less and cleaner.

At low temperatures, little or no feeding is done. Decisive factors are water temperature, activity, and the depth of the pond. In very cold conditions, food is often more of a burden than a help. In winter, ensure especially oxygen, free gas exchange surfaces, and calm in the pond.

Gasping for air can indicate oxygen deficiency, poor water parameters, gill irritation, heat, overstocking, or technical problems. Immediately advisable: increase oxygen, measure water parameters, check pump and filter, stop feeding, and look for changes in the pond. If symptoms persist, please seek professional advice.

Do not treat blindly. First check water parameters, temperature, oxygen, group behavior, and possible injuries. Medications without a diagnosis can do more harm than good. If a health concern arises, personal expert advice or a koi-knowledgeable veterinarian should be consulted.

The filter depends on water volume, stocking level, feeding amount, desired water quality, maintenance effort, and construction style. Plan it deliberately larger than just adequate. In the area Filter technology at Japan Koi Shop you will find fleece filters, Crystal Clear endless band filters, bio chambers, and other systems.

Chamber filters can be biologically strong but require more manual work. Fleece filters remove dirt very finely and conveniently, but consume filter fleece. Endless band filters also work very cleanly, reduce ongoing consumables, and are especially interesting if you want high water quality with less cleaning effort.

The Crystal Clear or CC endless band filters are proprietary filter products from the environment of Japan-Koi Wild/Japan Koi Shop. They are designed for koi ponds where mechanical pre-filtration, clean flow, and low maintenance are important. You can find them in the filter technology section under Crystal Clear endless band filters.

A fleece filter is worthwhile if you want very clear water, fine dirt removal, and little manual cleaning. This is especially interesting for Koi with good feeding and higher demands on visibility depth. Consider the ongoing costs for filter fleece and do not choose the size too small.

That is a typical sign of high dirt load, too little pre-separation, or too much manual work in the system. Brushes can work but are maintenance-intensive. If you regularly have to clean heavily soiled brushes, it's worth looking at modern fleece filters or CC endless band filters, as they remove suspended solids from the circuit much more comfortably.

The pump must match the pond volume, filter, pipe runs, height differences, and desired flow. Too little flow makes filter and UVC weak, too much flow can disrupt biology and separation. Pond pumps can be found in the area Pond pumps; for specific sizing, consultation is advisable.

Yes, in many koi ponds additional aeration is very useful. Koi, filter bacteria, and warm summer nights need oxygen. Especially with denser stocking, heavy feeding, or heat, you should not leave oxygen to chance. Suitable equipment can be found in the area Aeration.

For newly planned koi ponds, bottom drain and skimmer are often the cleaner solution because dirt is removed where it originates. Retrofits are possible but usually more compromised. If Japan-Koi Wild plans the pond construction or renovation, filter, pipe routing, bottom drains, skimmer, and equipment room should be considered together.

Yes, pond construction and filter systems are part of the consultation. Especially with high-quality Koi, the system is part of the decision: volume, depth, current, filter chamber, UVC, oxygen, and maintenance must work together. For pond construction, renovation, or filter planning, please use the consultation form or call directly.

Do not start with the fish, but with the target picture: How big should the pond be, how many Koi do you want to keep long-term, how much maintenance is realistic, and what budget is planned for equipment? After that come filter, pump, UVC, aeration, and only then the appropriate Koi selection. This creates a pond that brings joy and does not permanently cause problems.