Feeding your Koi as Water Temperatures Change

Everyone knows that water temperature plays a big role in how active koi are but a koi’s metabolism and ability to digest certain types of foods are also affected. Its critical that as temperatures drop with approaching winter or as temperatures increase with the onset of summer that you feed your koi the right amounts and at the right time. To illustrate some of the more important points of koi feeding schedules and how the are tied to water temperature I’ve created this infographic:

Koi Feeding Through the Seasons Infographic

I will be following up this infographic with a helpful chart on koi length, age and size so help you better understand how your fish grow.

By | 2017-05-15T02:17:15+00:00 October 16th, 2014|Food and Nutrition|14 Comments

About the Author:

I have been interested in fish for over 25 years. I have two degrees in marine science with a specialization in fish ecology and physiology (as well as a chemistry minor). Like many kids, I had a goldfish growing up but decades later took care of several koi ponds. Koi are such great pets and very accessible for many folks wanting to get into owning koi in a pond environment.


  1. Judy Humphreys October 24, 2014 at 8:14 pm - Reply

    Why ar my white koi (10-12 inch) turning pink? Nitrites-Neg, ammonia -Neg, salt content-0.29 for one week then will do a 20% water change for fall.

    • Koi-Care staff November 4, 2014 at 3:49 pm - Reply

      It has a lot to do with the food you are feeding your koi. Flamingoes are pink because they eat shrimp etc. There are special foods out there for koi that help with color.

  2. Tiffany November 17, 2014 at 9:12 am - Reply

    I have a black and white koi that I got from a friend a month ago. I think it’s about 1.5 years old, 20-22″ long. Ever since we got it…I noticed that it started to turn pink…almost peachy where it used to be white. I am feeding it the same food that previous owner used to fed it. The fish seems fine, doesn’t seem to eat as much as the other fish though. Is something wrong with this fish?

    • Koi-Care staff December 22, 2014 at 5:21 pm - Reply

      There’s a few factors at play when it comes to koi coloration.

      1) carotenoids in foods
      2) temperature (typically brighter colors in cooler waters)
      3) sickness
      4) stress (prob. the reason your fish is losing some of the bright white;new environment, new pond mates)
      5) age (usually seen as color and pattern changes from young koi to mature koi)
      6) during breeding

  3. usa ads November 26, 2014 at 6:59 am - Reply

    What about color enhancing food?

    • Koi-Care staff December 22, 2014 at 5:15 pm - Reply

      yes, there’s products like Saki-Hikari and Dainichi but they aren’t cheap. They are typically used by those that are involved in competitions.

  4. linda krodel January 31, 2015 at 10:26 pm - Reply

    I recently had to do a complete water change and will be replacing my filter. Most of the rocks were removed and the water lilies have minimal plant growth at this time of the year.,
    I was advised not to feed for the next 5 days and then gradually in small amounts.
    Will I starve them?
    The fish were previously doing well with 2 feeds a day but I was vacuuming and changing about 1/6 of the water due to algae problems.

    • Koi-Care staff February 8, 2015 at 3:26 am - Reply

      No, they won’t starve in that amount of time but I would suggest giving
      your filter media a jump start with something like “Microb-Lift” – it will
      help populate your filter media with beneficial bacteria.

  5. Ann Smith April 2, 2015 at 12:45 pm - Reply

    I’m very new to caring for Koi. When cleaning the round sponges in the filter I was using the hose. I later was told I should have used the pond water and the reasoning behind that. I honestly didn’t understand the purpose of the filtration system as far as the good bacteria, etc;. Now, one of my largest Koi (about 9″ long) had died and I’m very bummed out about it. It looks like it has an ulcer on both sides of it and the tail fin looks like it might have had a little rot. What should I do to protect the other Koi? I added an anti-bacterial solution I got at the local pet store and was told to continue for seven days. Is there anything else I should be doing as an added measure?

    • Koi-Care staff April 11, 2015 at 2:46 am - Reply

      a healthy koi won’t typically develop ulcers or fin rot in ideal conditions which means that its immune system was depressed or there was poor water quality conditions. If your fish was still alive you would want to isolate that fish in a separate pen and treat with a topical antibacterial but ultimately the source of the problem would be water quality so that is the first thing you need to address. Being springtime its a good idea to give your filter media containing the beneficial bacteria a boost with something like Microbe-Lift PL. You could also do water changes as well. Test your ammonia and nitrite levels. For a primer on how some of this works i have an article and infographic here (http://koi-care.com/understanding-biological-cycle-koi-pond/).
      Hope this helps, Grant

  6. Rick July 7, 2015 at 2:02 pm - Reply

    We just moved into a new house w/ a 8”x3’x9″ pond w/ pump waterfall. It has some string algae, water bugs, snails, etc. Can I just put small koi in and let them eat what’s in the pond w/o feeding?

    • Koi-Care staff July 13, 2015 at 3:14 pm - Reply

      its possible but you may have to supplement with floating pellets as well.

  7. ingrid September 28, 2015 at 12:35 pm - Reply

    Good morning, your site is very informative, my pond is clear I do have a UV light but my problem is on the stones or the waterfall i have green algae and would like to see the stones clean. How can I clean them without hurting my koi.

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