How to Clean a Koi Pond Safely and Effectively

Koi ponds are a beautiful addition to your home’s landscaping, but contrary to what you might think, they’re not always easy to care for!

Like any other animal, the koi in your pond need specialized care and attention. Cleaning their pond and keeping it sanitary will make up a large part of your koi ownership. 

It’s always a good idea to educate yourself before adopting any animal, so that’s exactly what we’ll be doing in this article – specifically, for cleaning your pond and care of your koi fish. If you don’t research how to keep your pond healthy and clean, you could end up with unhealthy fish, an unsightly or dirty pond, or worse.

In this guide, we’ll teach you how to care for your koi pond and the fish inside. We’ll be answering questions like how to clean a koi pond, how often to have a professional clean it, how to care for your koi fish properly, and more.

Do You Have to Clean a Koi Pond?

Yes! While large ponds in nature often have all the necessary organisms and microorganisms to function as a closed system, the same isn’t true for small, human-made ponds. Your pond needs thorough cleanings, water changes, and filter equipment to keep it healthy and thriving. 

This is because, over time, wild animals, debris, and other things (like fish waste) will make their way to the bottom of your pond. Too much junk can not only compromise the water quality, but it can eventually make your fish sick, also. 

So, yes – if you want to ensure the health of your fish (and the beauty of your pond), you do have to clean it occasionally.

How Often Should You Clean a Koi Pond?

A picture of koi fish in a pond.

How often you should clean your koi pond depends on how clean you want it to look and how fast it gets dirty.

For example, if your koi pond is located near trees that drop a lot of leaves into the pond, you may have to clean these out a few times per year (especially in the fall). However, if your pond doesn’t collect much debris, you may be able to get away with cleaning it once or twice per year. 

That’s only when it comes to deep cleanings, though. You should perform minor cleanings – like skipping the surface of your pond for algae and leaves and changing out a portion of the dirty water – on an as-needed basis. 

Do I Need to Drain My Koi Pond to Clean It?

You can clean your koi pond in many different ways. As we said above, you should deep clean your koi pond one or more times per year, depending on how quickly it gets dirty. Deep cleanings usually require you to drain your pond and clean out the debris at the bottom.

However, if you’re wondering how to clean a koi pond without draining it, you can do a small-scale cleaning of your pond without removing any water (or you can just empty it partially). For example, a pond vacuum can be great for cleaning debris off the bottom of your pond without needing to drain the whole thing. 

Additionally, your pond’s filter and other parts will need cleaning from time to time, too. You can simply pull these out and clean them off. 

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How Do You Clean a Koi Pond Without Killing the Fish?

As you might expect, the easiest way to clean your koi pond without risking your fish’s integrity is to refrain from disturbing them at all.

You can clean your pond with a skimmer, a net, or even a vacuum relatively successfully. While this won’t replace a thorough deep-cleaning every so often, it’ll definitely help.

The next logical question is this: how do you safely remove and keep the fish while cleaning the pond? If it’s time to deep clean your pond, the best way to do so without harming your fish is to drain your current pond water to a pool or container, then transfer your fish into it. 

This way, your fish will experience as little shock as possible. Sudden temperature or water quality changes can be harmful to your fish. 

How Do I Reintroduce Fish to My Pond?

When reintroducing fish to your pond, it’s generally safest to re-use some of the old pond water they’ve been resting in. However, if your pond water is too dirty and you need new water, you’ll have to do a few things first:

  • Make sure your fresh water is as close as possible to the temperature of your current water before adding your fish to it
  • De-chlorinate your fresh water (if necessary)
  • Ideally, only replace up to 50% of your water with new water at a time

By only replacing up to 50% of your fish’s water at a time, not only do you help retain the temperature of your water, but you help preserve some of the good bacteria and microorganisms in the water, too. 

Suppose your water quality is at a dangerous level, such as when it has very high ammonia levels. In that case, you can make several small water changes every day (equaling about 20-30% of the pond water) until the water quality is at an acceptable level. 

Koi Pond Cleaning Step-By-Step

When you’re ready to deep clean your koi pond, follow these steps to do it safely and correctly. 

  1. Gather your tools, such as nets, a receptacle for your fish, pumps, pond vacuums, filter replacements, de-chlorinator, etc.
  2. Scoop out any debris and pond scum at the top of the water. Do this several times per week to keep your pond clean and debris-free.
  3. Optionally, remove the koi from your pond. If you have a large pond and don’t plan to drain it, your fish may have room to stay away from you as you clean it. Make sure to drain enough water into your holding tank to keep your koi fish safe and healthy while you clean the pond. 
  4. Vacuum or scoop any scum, debris, or gunk on the bottom of your pond. If your pond is filthy, you can use a hose to spray the gunk off rocks and fixtures gently, but be careful to leave helpful bacteria and algae intact. Use this time to replace any filters and clean any water accessories, too.
  5. Return at least 50% of your old pond water to the pond. Mix with fresh, dechlorinated water that’s the same temperature as your pond water. 
  6. Return your koi fish to your pond, keeping an eye on them to make sure they’re healthy and content.

Koi Pond Cleaning Equipment

You’ll need different equipment depending on how you want to clean your koi pond. For example, an always-on filter will help keep your pond cleaner over time, a skimmer will help take care of routine debris, and a pond vacuum will help clean sunken debris off the bottom. 

These are just three examples out of many. If you’re wondering how to clean a koi pond while making the most out of your available tools, check out our recommendations below.

Pond-Skimming Net

A pond-skimming net is one of the essential tools for pre-emptive pond cleaning. By skimming your pond several times per week, you’ll end up with less debris to clean out later. This nifty net functions both as a pond-skimming net and as a debris-clearing net that can clean out the bottom of your pond, meaning you can use it for daily cleaning and deeper gunk removal. 

Pond Vacuum

While you don’t need a pond vacuum for cleaning out your koi pond, a vacuum will make your job significantly quicker and more comfortable. However, a pond vacuum is expensive – professional pond vacs can cost upwards of $400. 


Water de-chlorinator, also known as water conditioner, is essential for keeping your fish healthy and happy. Water conditioner removes chlorine and chloramine from your hose water before you add it to your pond, and some water conditioners, remove other harmful chemicals like ammonia, too.

Pond Pump

Like a pond vacuum, you don’t necessarily need a pond pump to clean your koi pond successfully, but having one makes your job significantly more comfortable. However, unlike a pond vacuum, pond pumps are very affordable. You’ll be forced to remove water from your pond by hand with a bucket without a pond pump. 

Fish Net

If you only have small koi in your pond, you may be able to remove them from your pond with your skimming net. However, if you have large koi (or a small skimmer net), you may find this task difficult! A large fish net, like this one, is essential for removing large koi from your pond, and it can help when capturing quick-moving small fish, too.

Koi-Sized Receptacle

If you plan to remove your koi from your pond while you clean it, you’ll need a safe and appropriately-sized place to keep them in the meantime! If you have small fish, you may be able to get by with a storage tote or kiddie pool, but you may need to get a bit creative if you have large koi. A stock tank can be great for holding your large koi fish. 

Should I Have My Koi Pond Professionally Cleaned?

You don’t need to have your koi pond professionally cleaned, but it’s always a good idea if you can afford it. If you can get your hands on the proper cleaning tools (or you have the patience and time to do it without them), you can get excellent results by cleaning your koi pond yourself. 

That being said, a professional cleaning only needs to be done once or twice a year, and you can rest assured that the professionals you choose will have the expertise to leave your koi pond healthy and thriving. If you’re not confident doing it yourself or you don’t have the time to devote to it, hiring a professional is never a bad idea.

Koi Pond Cleaning Costs and Service Companies

How much your koi pond costs to clean depends primarily upon how large it is. Larger koi ponds will require more cleaning, of course, and if the cleaning company will be pumping more water out of your pond, this will also take more time and energy. 

Your koi pond may also be more expensive to clean based on other factors. Of course, which factors affect the final price depends on the company you decide to work with, but some of these factors might include:

  • Having an extra-dirty pond
  • More fish
  • What kind of filter (or lack of filter) you have
  • Whether or not you have a net over your pond to catch leaves and debris

HomeAdvisor says that the average yearly maintenance cost for a koi pond is about $2,000, but depending on your pond’s size, it can range between $450 and $5,000.

If you have a tiny pond with only one or two fish, you can expect the cost to be close to the low end, but if you have a large or filthy pond with lots of fish, expect it to be close to the high end. 

When looking for a koi pond cleaning company, you should ideally look for one that specializes in cleaning koi ponds. If you can’t find one, a regular pond cleaning company may be good enough. Make sure to look for one with good reviews and a proven track record, and always be sure to ask if they can perform the services you need.

Two images of koi fish. Text reads the best way to clean a koi pond.


Now that you’ve read over this article thoroughly, you should have a good idea of how to clean a koi pond, the tools you need to do so, and how often you should have it cleaned. Cleaning a koi pond can be tedious, but having the right tools makes it much more manageable. 

If you don’t have the time or energy to do it yourself, having a professional clean your pond once a year can be an excellent investment, too. However, don’t forget that you can do just as well on your own with the right preparation.

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