Koi Pond Care for beginners

Koi Pond Cleaning Tips | Fitz's Fish Ponds

About Koi fish

Koi Pond Care for Beginners / Koi pond in your backyard is undoubtedly a peaceful place where you can spend time and have mental relaxation. Caring for a koi pond is a sweet pleasurable responsibility, which you can fulfill easily by learning some tips. To understand and learn about care practices needed for maintaining a koi pond, one must be aware of the nature and habitat of Koi fish. Koi fish are bright and big ornamental fish derived from the carp (a large group of freshwater fish). They are very active and peaceful fish. They can survive for several years and you can keep them in your garden pond for a long time, but their long-term survival needs a peaceful and optimum environment. 

Planning to build a koi pond

Selection of fish

Koi fish are available in varieties of shape, color and size so make the selection of koi fish according to the size of the koi pond you are planning to build. Usually, koi fish can grow up to 3 to 4 feet long so your pond must be of a minimum of 8 x 6 feet at the surface and 4 feet deep. Preferably, one must try to build the pond as big as possible because the larger the amount of water in the pond, the lesser will be the chances of temperature variation due to weather changes. 

Quarantining Koi fish 

Before introducing koi fish to your pond, one must not directly dump them into the pond; it is essential to make them stabilize and acclimate. For this, quarantine the koi fish for a minimum of three weeks into a holding tank that has 50 gallons of water volume (for every 3 fish of 10 inches long). You can use a large tub or kid’s swimming pool for this purpose too but make sure it is strong enough to bear the weight of water otherwise it may collapse and you will lose your fish. This holding tank must possess a cycling filter for removing bad bacteria. You also have to use a net for covering the top as stressed fish might jump out of the strange environment. Day by day, add pond water to the holding tank. It helps in making the temperature of the holding tank much similar to the pond.  This will let the koi move into the new environment in a controlled manner.

Introducing koi to the pond 

Once the quarantine period is over, place the fish in a plastic bag and allow them to float in the pond water for 25 to 30 minutes to adapt to the new temperature. After that, gradually fill the fish bag with pond water to observe other factors like pH, alkalinity for the next 10 to 15 minutes. At last, immerse the fish bag in water and let them swim out of the bag.

Feeding Koi fish

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After the koi entered the new pond, let them rest for a day and then offer them a portion of food. Ideally, it is recommended to feed such an amount of food that koi can eat within 5 to 10 minutes. If the food remains uneaten even after 10 minutes, it means you have overfed them. By nature, koi are omnivorous and can continuously eat so feeding them in excess can cause severe health issues.

This over-feeding can lead to decay of the uneaten food that can decrease the water quality of the koi pond. It can also cause bad bacteria to grow and can make the water cloudy. Choose high-quality fish food that floats on the surface rather than sinks to the bottom so that you can take it out easily if remain uneaten.

Keep the pond aerated


Maintaining the oxygen level of water is a crucial process and essential need for a fish to survive. Low aeration means that the pond has a high concentration of carbon dioxide. For keeping the pool aerated, install an inlet to your pond that allows the oxygenated water in and deoxygenated water out. You can also add a bubbler, fountain, or waterfall to keep the water in contact with air. Another way to keep the pond aerated is to move the water from the bottom to the top surface using a bottom drain system that could circulate this process for 24 hours. This will let the water with less oxygen come up and contact with air. You can also bring in some oxygenated aquatic plants to enhance oxygen levels.

Filtration and pumping system

Arrange the filtration and pumping system according to the amount of water you have in your pond. Regularly examine the system to make sure the filtration and pumping are functioning without any blockage with any debris or uneaten food. Try to arrange a big enough pump that could circulate all of the water after every one or two hours. This would let your pond become stagnant free. Choose such type of filter that not only helps to maintain the overall water pH around 7 but also removes debris and waste. Keep in mind that the pH below or above this range can be dangerous for your koi health. Remove trapped waste from filters regularly even if the collecting basket is not full.

Filtration is done in two ways i.e. mechanical or biological. Mechanical filtration allows filtering solid waste like plants, leaves, plastic, sticks, and insects whereas biological filtration protects the pond from toxic and chemical wastes. It is recommended that when you go for buying a filtration system, purchase a pond skimmer and couple it with a biological system. The skimmer helps to clean the debris from the water surface and the biofilter produces beneficial bacteria and converts the pond waste into harmless products. This biofilter is placed at the position of the pond where there is the beginning of the waterfall.

Maintaining pond’s temperature

Koi is a carp that can survive in cold regions too as they hibernate themselves under the water in winters. Hibernation of koi during winter can slow down their digestion process so they don’t need to eat much. If the surface of the pond gets to freeze, you can use a floating heater or de-icer that can sustain a hole in the ice for adequate gas exchange. During summer seasons, the rise in temperature above 75oF can create a problem for your koi, as it decreases the oxygen level in the pond. To avoid any mishap, use a temperature gauge regularly to keep a close eye on your water temperature. For making your water naturally cool, you can use aquatic plants or aerators. It will keep your pond oxygenated. Also, try to plant lily pads and install your pond near shaded trees. This will drop the temperature of your pond naturally during the summer season. 

Maintaining water quality

The main element for maintaining water quality is the addition of de-chlorinator to pond water before introducing koi in the pond as it removes all the traces of chlorine. If the koi gets ill, it is usually due to reduced diet or poor water quality. You can readily notice it with their unusual swimming patterns. Examine your pond regularly to minimize the risk of illness in koi. The water quality decreases due to the evaporation of pond water. Mostly in summers, water evaporates from the pond leaving behind minerals that could result in increasing the concentration of minerals in the pond. Also, keep checking the pipes and valves that are delivering water to the pond as they might become rusty and deposited with minerals after some time.

The best way to take care of water quality and to prevent your koi from toxins is that you have to remove 10% to 15% of ponds water monthly and replace it with fresh water. You must possess a water test kit to monitor water quality to prevent your koi from any harm. Do this assessment once a week as fish might look fine even in poor quality water for some time. Keep adding anti-parasitic medication after every few days to lower the risk of infection in koi.

Protection against predators 

Besides the importance of maintaining water quality, the risk of predators is also a threat to koi. Raccoons, domesticated cats, and minks living nearby can easily reach your koi and harm them. To protect your koi, try to build some cave or waterfall behind which they can hide. A bridge over the pond can also help to keep your fish hidden from the view. Installing an electric fence around the pond can be useful to eliminate this problem but it may diminish the beauty of the pond. Motion-activated alarms and pet dogs can be beneficial in alarming any uncertain incident.

Clean koi pond regularly 

The best time for cleaning the koi pond is the time when they are having their lunch. Take this opportunity every day for 10 minutes to keep the pond water fresh and clean. Take out leaves from the pond surface that are falling off from nearby trees and clean debris from the edges of the pond otherwise, they may sink to the bottom of the pond and make a sludge layer. You can remove the sludge using a pond vacuum that draws the mud from the bottom. Make sure you leave some of the sludge that could help the algae to grow. Algae are beneficial for the garden pond but their excess can harm your koi. Plants have many benefits if added to your pond but if they are taking over too much space of the pond surface, it is better to cut them off. It may reduce oxygen content for your precious koi.

Don’t Overcrowd the pond

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Can you enjoy the beautiful sight of the pond if it is crowded with several fish? Of course not. Koi requires plenty of space to grow and swim. An overcrowded pond is an indication of poor monitoring of the pond. To avoid this, keep a keen eye on the koi growth. Koi love to swim freely; over-crowdedness can make the fish uncomfortable. It is advisable to keep the koi separate from other families of fish, as they do not like to swim with them. They sometimes become aggressive if you overcrowd them and can most likely produce excess ammonia-containing waste, which can increase algae, and deplete dissolve oxygen.

Check for pond leakage

As discussed earlier, the water level of the pond may decrease due to evaporation but if you notice that this level is increasing rapidly then you must check for leakage in your pond. Normally, a koi pond loses half-inch of water in a single day due to evaporation but if the loss is greater than that, it is an indication of some leakage and immediately requires repair. To cater to the leakage issue, firstly drain all of the water from the pond then repair the area from where the leakage is happening. Use the right repairing material like concrete, rocks, and soil. The leakage could occur due to holes, cracks, and any disconnection in the pond’s accessories. If you cannot repair it on your own, you can seek help from pond repair professionals.

Bottom Line

Koi Pond Care for Beginners. Koi are colorful attractive pets that you can keep for your relaxation. Installing a koi pond in your garden will not only add beauty to it but can also provide you peace of mind.

Building a koi pond is easy but maintaining it in a healthier way is crucial. Your koi’s health depends upon your care and attention towards them. Sometimes they can be difficult to handle so you must have a proper plan before making a pond and to provide koi with the maximum benefits. In short, for making a koi happy and providing them a healthier environment, a koi pond must have the following conditions :

  • Oxygen rate of minimum 6mg/liter
  • Zero percentage of nitrite, chlorine, zinc, copper, iron, and ammonia
  • Below 20 ppm of nitrate
  • pH ranging between 7 to 8.5