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Inheriting a koi pond along with the purchase of a new home can be exciting but daunting, especially for a novice. If you are lucky, the previous homeowner provided detailed instructions on the pond and its care. However, that often is not the case.

It can be helpful to understand exactly what you’re undertaking with your new koi pond. The following are some things to consider when you are deciding whether to assume ownership of a koi pond.

Are You Ready for Koi?

You are probably more ready than you think. You don’t need to be an expert or a pro to enjoy the perks of koi ownership. The hardest part is designing and installing the pond with the correct elements, and that job has (hopefully) been done for you. After that, koi ponds do most of the work for themselves. In general, homeowners find that koi pond maintenance easily fits in with regular backyard maintenance.

As long as you provide clean water, shelter, and high-quality food, your new koi can take care of themselves pretty well. These hardy fish are able to thrive in most environments. The average koi grows between 20 and 25 inches long and lives between 25 to 45 years. More than 100 varieties of koi exist. If the previous owners did not identify the types in your pond, you can use an identification guide to explore what you are getting.

Get Familiar with Filtration

High-quality biological and mechanical filtration systems are vital components of maintaining the water quality your koi will need. Biological filtration occurs when beneficial bacteria break down ammonia and nitrite in the pond. Mechanical filtration captures small particles of waste and debris. The filter should be able to cycle all the water in your tank at least once an hour.

Identify Equipment

There’s a lot to explore when it comes to potential koi pond equipment, but these are some of the more essential elements that you will want to identify and inspect.


The pump is the heart of your pond’s recirculation system. When you find the pump, make sure it’s running and doesn’t appear clogged or littered with debris. If something doesn’t seem to be working right–or if the pump’s in a hard-to-access location–you might want to consider making some changes.


Every pond needs a liner to stop water from leaking. Rubber-lined ponds are better than rigid, plastic ones because they are more durable, easier to filter, and, ultimately, easier to care for.


Water skimmers save you lots of manual labor, as they remove about 90 percent of leaves, sticks, and other large debris that enters the pond. You should find them sitting along the edge of the pond, letting water flow in through an opening in the front.


Aerators help to maintain appropriate levels of oxygen in the water, which koi need to survive. In the summer, they help stabilize the oxygen levels that naturally dissipate in heat. In the winter, they open a hole in pond ice, breaking the surface tension and removing carbon dioxide to keep fish safe.

Know Your Water Quality

Regular water quality checks are essential to ensuring you are housing healthy fish. Test water for pH levels, ammonia, nitrites, and nitrates, all of which can harm fish when out of balance. If your pond has not been regularly maintained during the home sale process, you will want to begin by checking the water daily. After ammonia and nitrite levels have reached zero and nitrate levels are within an acceptable range, you can reduce the frequency of checks. Depending on the pond, you will need to replace 10 to 20 percent of the pond’s water about once every week or two.

Take Stock of What You Have

The pond’s volume and the number of fish it holds are large determinants of what it needs. Your pond should hold at least 1,000 gallons to start, plus 200 gallons for each koi. An overcrowded pond can lead to aggressive behavior, poor water quality, and sick and unhappy fish.

Because koi are non-aggressive, they do well with a number of aquatic companions. It’s a good idea to know what else, if anything, resides in your pond along with the koi. Goldfish are a popular companion species and don’t require any additional specialized care.

Aquatic plants increase oxygen levels and contribute to the pond’s biological filtration. Additionally, plants create natural hiding spots to help koi remain safe from neighborhood predators. Ideally, your pond will contain a mixture of floating plants, shallow marsh plants and submerged plants.

Financial Considerations

Since each backyard pond is different, maintenance costs can vary significantly. The two main drivers of cost are the pond’s size and condition. Larger ponds will be more expensive to maintain, and ponds that haven’t been cleaned in a long time will cost more to revitalize.

You will incur some energy costs running your pumps and aerators and will periodically need to replace parts. Also, consider the regular cost of food and occasional medication treatments for your koi. Whether it’s an unexpected financial emergency or just shifting economic priorities over time, the price tag, though generally reasonable, can become burdensome if you don’t plan for it.

Feeding Your Koi

Choosing high-quality food made specifically for koi is important for their health and for helping them to reach their size and color potential. We recommend Blue Ridge Koi & Goldfish Food.

Because koi metabolisms shift based on temperature, adjusting the type of food you give your fish when the seasons change is essential. An all-season formula is appropriate when temperatures are above 65℉. From 50℉ to 65℉, you’ll need to switch to easily digestible food. Wheat germ-based formulas are the most popular choice, like Blue Ridge Cool Water Wheat Koi and Goldfish Food. Stop feedings completely when water temperatures drop below 50 degrees.

Water temperature also plays a role in determining the frequency of feedings. Koi can eat three to four times a day when temperatures are above 70 degrees. One to two times daily is appropriate for temperatures between 62℉ and 70℉, and once daily or every other day at temperatures between 50℉ and 62℉.

Rehome if Necessary

If you aren’t interested in keeping koi, you can ethically rehome them. An empty pond can still be an attractive backyard feature, and it is better to find the koi a good home than to not care for them properly. Several rescue organizations also exist around the country that can help.

Are you ready to add to your new pond? Shop our full selection of koi and pond goldfish today.

2 responses

  1. Debbie Brosnan :

    I have a friend in Lincoln, CA who has 3 large koi in need of new home as her pond in only 50 gallons and there is not enough room for all the fish she has (they range in size between 12 & 18 inches) Any suggestions for rescue group (she has placed posts in multiple “chat sites” w/o response)

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