Koi Ponds FAQ

Pondliner.com for the answers to all your questions about koi ponds.

Let the experts at Pondliner.com help answer all of your questions about koi ponds. Read below for all the information and answers you need to keep your koi fish and pond healthy and beautiful.

How many koi can I have in my pond?

No two koi ponds are exactly the same, but a good rule of thumb is to have only one koi for every 100 to 200 gallons of water in your pond. This way the koi will have enough room to swim around once they’ve reached their full, mature size.

What kinds of koi can I buy from Pondliner.com?

We carry a large variety of koi and goldfish. You can choose from the following categories of koi: Decorative Koi, Decorative Butterfly Koi, Select Koi, Select Butterfly Koi, Premium Koi, Premium Butterfly Koi.

If you want to add goldfish to your pond as well, you can choose from the following varieties: Comet Goldfish, Sarassa Coment Goldfish, Shubunkin Goldfish, Fantail Sarassa Goldfish, Fantail Calico Goldfish, Mixed Goldfish.

How large will my koi be once they are full grown, and how large should my pond be to accommodate them?

In five years a koi can grow to be 18 – 24 inches long. Because of this, you need to make sure they have enough room to grow and live. Koi ponds should have at least 1,000 gallons of water, and it needs to be at least 2 ½ – 3 feet deep. If you live in an area that experiences especially harsh winters, you may want to check with a local pond supplier to see if your pond needs to be even deeper.

What do I need to do to keep my koi healthy?

This answer has multiple parts. First of all, you need to keep in mind that the health of your koi is directly related to both water quality and proper nutrition. With that in mind, the following points should help keep your koi healthy:

  • Keep the pH of your pond water between 6.8 and 8.0. Monitor its ammonia and nitrate levels to make sure they always remain at zero. If these numbers go above zero at any time, that means you are over-feeding your koi or there are too many of them in your pond.
  • Remove 25% of your pond water and replace it with de-chlorinated tap water once a month.
  • Feed your koi only fresh, nutritionally balanced food. A complete selection of our fish food can be found here. Don’t overfeed your koi, because that will lead to an increase in ammonia and nitrate levels.
  • Don’t add too many koi to your pond. Overcrowding is the main cause of disease outbreaks and fish loss. You should have roughly one koi for every 100-200 gallons of water in your pond.

Do I need a pond filter in my koi pond?

Yes, all koi ponds need a filter. Fish waste, along with decaying plant matter, can create a build-up of toxic materials in your pond. A pond filter will help remove these toxins and ensure that your fish have a healthy environment in which to live. There are many different varieties of pond filters available at Pondliner.com. Research your options to find the best model for your pond.

How do I know what food to feed my koi?

The diet for your koi should be dictated by the temperature of the seasons. In cooler temperatures, when your pond water is between 42 degrees Fahrenheit and 72 degrees Fahrenheit, your koi need a high carbohydrate/low protein diet. Your koi’s metabolism slows down when the temperature is cooler, so they need less food with very little protein in it. Pondliner’s Spring & Autumn Pond Food is an ideal choice. Once water temperatures fall below 42 degrees Fahrenheit you should stop feeding your koi altogether.

When water temperatures are warmer, above 65 degrees Fahrenheit, your koi need food that has greater amount of protein, fasts, minerals and vitamins in it. The Pondliner Pond Care Summer Staple Pond Fish Food is great for this, because it has 13 sources of easily digestible protein and a full spectrum of amino acids.

Will my koi eat my plants?

Although some koi have a tendency to root up plants, you can prevent this from happening by: using large cobbles on top of your planting pots; or using plant protectors to keep your koi away from your plant roots.

Will my koi reproduce?

Koi lay eggs to reproduce. This spawning usually occurs in the spring, and hundreds of eggs are laid. However, many of those eggs never get fertilized and/or they are eaten by adult fish. However, some will hatch and some of those can survive to adulthood. You need to monitor the spawning in your pond to make sure you don’t end up with an overpopulated pond.

Have questions about koi ponds construction? Want to build the perfect koi pond for your backyard?

Visit our koi pond construction page to learn more about the supplies you need to create a beautiful koi pond. If you have additional questions or want more information, please contact one of our representatives through our website or call 1-866-766-3548.

You can also purchase one of our koi pond kits, to make sure you have all the supplies you need to build beautiful backyard koi ponds. Koi pond kits are especially beneficial for the do-it-yourself pond enthusiast, because they take the guesswork out of pond assembly and help you create functional ponds with ease.