Koi Pond Maintenance


Koi Pond Maintenance through the 4 Seasons

Once you are done building and stocking your pond, you are not finished. Koi Pond Maintenance is a process that varies by location and is required to protect the water quality and appearance of your pond. This page describes how to maintain a pond in zones where the winter temperature drops below freezing and the koi go into an extended hibernation. Below is a checklist of activities explaining koi pond maintenance during each season.

Spring – Time to Open Your Backyard Pond

1) If you covered your pond with netting as I do to keep out leaves in the fall. Remove this netting.

2) Clean the pond and the filter system. Most of the books I have read recommend vacuuming the bottom of the pond at this time but I have never found that to be necessary. I do clean the filters thoroughly. I only do this once a year and spring is the most convenient time since I have not turned on the pumps yet and the biological filters have not been restored to full activity.

3) Re-connect pond pump and filters.Make sure that the water level is above the skimmer and turn on the pump to start circulating the water through the filter system and if drive the backyard waterfall. if you have one. I do this once the daytime temperatures consistently exceed 40 degrees F. I add live cultured bacteria at this time to jump start the biological filters. Test the water conditions to monitor the ammonia and nitrite levels. If they remain within tolerance you can skip adding the bacteria. Test the water at least once per week during this time. Once the water is flowing, check the skimmer once a day and remove any debris. I usually do this when I feed the fish and clean the leaf bag if any algae have accumulated.

4) Using the prescribed chemicals treat the pond against bacterial and parasitic problems. I have not always done this but during the spring start up is when I have found I am most likely to lose any koi.

5) Once the water temperature reaches 40 degrees F you can start feeding your fish again. During the colder months it takes them more time to digest food since the cold water lowers their metabolism. To help avoid digestive disorders and illness, a wheat germ diet is recommended and there are commercial offerings that are especially designed for feeding koi during these transition periods. Even with this diet the fish should be fed sparingly – once a day for no more than what they will consume in 5 minutes. Once the water temperature is consistently above 50 degrees F you can feed the fish their standard diet 2 to 3 times per day. ALWAYS AVOID THE TEMPTATION TO OVER FEED THE FISH AND REMOVE ANY UNEATEN FOOD FROM THE POND!


Summer – Time to Enjoy Your Backyard Pond

1) This is the time of year to enjoy your pond. You can feed your fish several times a day (if you like) as much as they will consume in 5 to 10 minutes. If I am pressed for time I feed them only once a day. If you go on vacation don’t worry because they can easily go 10 days to 2 weeks without regular feeding. In a larger pond with a small fish population they may be able to exist indefinitely on the natural food that is available in the pond.

2) If your water quality is good, spawning will take place in late spring or early summer depending on temperatures. Many of the books I have read recommend using spawning ropes or mats to remove fertilized eggs from the pond and raising the fry in a separate tank. This is to avoid the eggs or fry from being eaten. I have found this to be an unnecessary step. As long as the koi pond is not overpopulated, the water quality good and there are adequate hiding places, new fish will be born and survive every year. After 8 years the majority of fish in my current pond where born there. The frogs and larger fish keep the total population in balance. If you want to maximize the number of new koi and maybe try to sell them then spawning ropes make sense. Other than that you will soon have far more koi than your pond will support.

3) I fertilize my lilies and bog plants in late spring and early summer and then repeat that every month to 6 weeks until fall. If you want to add floating plants such as hyacinth this the time to do that. Bear in mind that these plants multiply rapidly and will to be having removed in the fall. In general I want my lilies and floaters to cover 60% to 70% of the surface area of the pond to provide cover and shade for my fish.

4) My general routine for summer is to feed the fish in the morning and evening (before leaving for work and then after returning). I sometime feed them for fun mid day on the weekends. The fish do recognize me walking down from the house and get quite excited and come into the shallow areas of the pond. I generally feed them in the same location and they know where to go. ALWAYS AVOID THE TEMPTATION TO OVER FEED THE FISH AND REMOVE ANY UNEATEN FOOD FROM THE POND! I also clean the skimmer during the evening feeding. It takes 10 to 20 minutes per day and that is basically all I do. I believe that the pond is there for my enjoyment not to turn me into it’s slave working on a bunch of not necessary tasks. However, if you have the interest and drive you can do as much work as you want enhancing and maintaining a pond.

5) If the fish do not come enthusiastically to the feeding I know something is wrong. This generally means a predator (in my case the Great or maybe not so great Blue Herron) has penetrated my defenses.


Fall – Time to Prepare Your Backyard Pond for Winter

1) In late summer/early fall I increase feeding to help the koi fatten up for the upcoming winter hibernation. When the water temperature drops below 50 F, I switch to wheat germ based diet and cut back on the amount of food. The koi’s behavior will tell you what to do since they will begin to slow down and eat less as the temperature drops. When the water temperature drops below 40 F I stop feeding all together. ALWAYS AVOID THE TEMPTATION TO OVER FEED THE FISH AND REMOVE ANY UNEATEN FOOD FROM THE POND!

2) End of October or early November, I cut back my water lilies and move the pots into slight deeper water. I cut back on my rushes, do the same with my irises and remove the cannas form the pond and move it in doors. This is the biggest and least pleasant job I have in my total pond maintenance schedule.

3) I turn off my pumps and remove them from the pond. I store the pump for the winter in my basement in a bucket of water to keep the seals form drying out. My experience has been that the pump last 2 to 3 years before needing to be replaced

Deicer small 150x150 Koi Pond Maintenance

Use a floating deicer or other device to always keep some open water in you pond

4) I place my deicer in the water. This is a thermostatically controlled heater that keeps the small hole in the ice so gases can be exchange with the atmosphere. A totally frozen over pond can lead to a fish kill due to lack of oxygen.

5) I live in an heavily wooded area and when the leave change colors, After cutting back on the plants, I get out a large net and use it to cover my entire pond and filter. Excess leaves in the pond will eventually decay and hurt water quality.


Winter – Time to Wait for Spring

1) In the winter I do basically nothing. I just make sure that the deicer is working and that the any snow falls has not pushed the net into the pond. Other than that I look forward to the spring when my backyard pond comes back to life.

Koi Pond Maintenance can be relatively easy and actually enjoyable as long as the pond is properly constructed and stocked.  Over populating with fish, excess feeding, excess sunlight and under filtration/circulation of the water will lead to unsightly algae growth and fish kills neither of which are very pleasant to deal with.


Next discover the colors and patterns that can be created by Breeding Koi

Leave a Reply

Your email address will not be published. Required fields are marked *


31,360 Spam Comments Blocked so far by Spam Free Wordpress

HTML tags are not allowed.