Search

Essential Tips for Koi Fish

Updated: Apr 26

So you’ve finally gotten that beautiful Hi Utsuri, or Yamabuki, or some other koi imported straight from Japan from Select Koi. Congratulations! You’re now the proud owner of a unique, original piece of living art. But, what now? How can you ensure you’re koi are happy and healthy?


In order to take care of your koi, grow them to a healthy weight and length, and make sure they don’t get any diseases or illnesses, there are a variety of things you’ll need to manage. There are many mistakes that koi keepers can make along the way, but this list of essential tips for koi fish will get you started on a path to success.


With Select Koi, we’re here with you for every step of the process. From initial acclimation to ongoing maintenance, should you ever encounter a problem with your koi or have any questions, give us a call! Our expert koi selectors are happy to help you troubleshoot whatever the issue is. We urge you to take advantage of this, as the last thing we want for you is to have to replace your dream koi. We care about the koi just as much as we care about your success as a koi holder!


Disclaimer: Keeping koi is not hard! Koi naturally want to coexist with each other and bring joy and tranquility to the home. They are hardy fish, able to thrive in a variety of climates. Follow these simple steps and you’ll be well on your way to a peaceful koi pond of healthy, happy koi.


Koi Care Explained

This list of essential tips for koi fish will help you ensure the success of your koi pond, and the health of your koi. If you’re thinking of installing a koi pond, or owning koi, keep reading to get an idea of what you have in store. Knowledge is power! Don’t be overwhelmed; once you get a routine schedule down for your koi, you’ll be well on your way to a long standing relationship with your koi. There are also ways to automate this process, such as automatic feeders and automated water changes.


  • Feeding: This is the first thing you’re likely wondering about! There are so many options on the market for great koi food, but the bottom line is ensuring the food contains all the necessary nutrients for your koi to thrive. In the wild, they are omnivores, eating things like algae, plant matter, flies, and animal matter. A balanced diet of carbohydrates, vitamins, minerals, and protein is what you need. In order to maintain beautiful koi, there are a variety of different feeds that accentuate color. It is recommended that the koi are fed every 3-4 hours, and all of the food should be gone within 5-10 minutes. If it is not gone within 5-10 minutes, feed them less next time. You can purchase an automatic koi feeder if you prefer. At Select Koi, we only use (and sell) one type of koi food: Nijikawa Koi Food. This includes a growth formula, premium professional grade, and 4 seasons.

  • Growing: If you bought a tosai or nisai from us, or from Value Koi, you’re probably curious on the best ways to grow your koi larger. It’s important to invest in high-quality koi food, with all the necessary carbohydrates, minerals, and vitamins needed for growth. Higher-quality means they’re receiving more nutrients with each feeding. You’ll want to feed them more during summer months, when their metabolism picks up.

  • Quarantine: This is an absolutely crucial aspect of keeping koi. Any koi collector worth their salt will have a separate quarantine koi pond. Even the most well-tended Nishikigoi can carry diseases, parasites, bacteria, fungus, or worms. Transportation can be very stressful for koi; this can compromise their immune systems, making them susceptible to illnesses. Quarantining koi helps to prevent those illnesses or bacteria from contaminating your healthy koi.

  • Treating sick koi: Similar to people, koi will act differently if they are sick. You may notice your koi isn't eating or it’s lingering on the bottom of the koi pond or at the surface. Other signs of sickness are discoloration, keeping its fins tight to its body, and its rubbing against surfaces. There are 3 main treatments, dependent on symptoms and ailment; physical removal (parasites and worms), dewormer, and broad spectrum disease treatment.


Habits to Master for Success in your Koi Environment

Just like humans, the thing they breath must be optimized to their health. If you were to introduce carbon monoxide to our air, we wouldn’t survive, similar to how introducing harmful contaminants or chemicals to your koi’s water would lead to disease and illness, even death.


This will cover mainly outdoor ponds exposed to the elements, with an indoor, aquarium-specific blog post to come in the future.


  • Filtration: In order to keep that water clear, free of algae, a healthy environment for your koi, you’ll need a proper filtration system. This will keep the water free of waste (which turns to nitrates, which cannot be dissolved), leaves, and . This consists of a bottom drain, skimmer, UV light for sanitization and algae control, and, of course, a filter. The filter is full of small plastic beads called “medium,” and they’re essentially bacteria magnets. All the waste and harmful bacteria will wash out of the filter, allowing clean water to return to the pond.

  • Water Quality: You’ll definitely want to closely monitor the quality of your pond’s water. Either using an at-home testing kit, or by taking a water sample, staying on top of your pond’s salinity, pH, KH (a measure of alkalinity), and GH (general hardness, or the concentration of minerals), and levels of ammoniums, nitrates, and nitrites. Though koi are freshwater fish, they will do fine with salinity of 0.5% which is good for acclimation and parasites as well as ammonia spikes.

  • Scaring off predators: Depending on where you live, your outdoor pond may be at risk to dangerous, hungry predators like snakes and birds. There are a variety of options for scaring off predators, from heron scarer fake floating fish, a decorative metal grate over the top, nets, giant eyeball fixtures (yes, it’s a real thing!), or a series of strings. A net will also keep your koi from jumping out of the pond.

  • Temperature: The ideal temperature for Nishikigoi is 75.2 °F to 78.8 °F. While they are hardy fish, able to withstand temperatures from 46.4 °F to 95.9 °F, you’ll want to stay within that 75.2 to 78.8 temperature range. Speak with our knowledgeable koi selectors about how you can be proactive about your pond’s temperature depending on your specific climate.

  • Volume: The more koi you have, the more water you should have in your pond. We recommend a depth of at least 4 feet, with length x width of 6x8 to protect your koi from predators and from bumping their heads on things (this is especially important for the Tancho variety!). This is 1077 gallons of water. There is a maximum number of koi that can live in 1077 gallons of water, ~6 koi. 15 koi will need ~3200 gallons of water. These figures can be manipulated based on water change regiments, feeding habits, and filtration.

  • Aeration: This is easily one of the most important aspects of keeping your koi happy. They need loads of fresh oxygen in that water to survive, at least 5 mG/L. You can do this with falling water (think waterfall or water fountain) or an air stone at the bottom of the pond.

Select Koi: Dedicated to Your Success

By following these essential tips for koi fish, you’re guaranteed success. There are many things you can do to automate this process, like automatic feeders and automatic pumps & filter systems for automatic water changes. Water changes may not be possible if you have a mud pond, obviously, which is the koi’s native environment.


When you make a purchase from Select Koi, you’re also working together as a team with Select Koi. We’re rooting for your success as a koi collector! If you ever find your fish are looking a bit slow, have some strange discolorations, or are exhibiting other strange behaviors, give us a call. If you’re noticing your pond is much too green or you need other tips on keeping up with your pond’s maintenance, we can help with that also! We’ve got your back through the whole process.


81 views0 comments
Subscribe here!