How Long Can Koi Fish Survive Without A Pump?

Koi fish are beautiful but require a lot of knowledge and care to maintain. One of those aspects is the environment of the pond.

How long can koi fish survive without a pump? Without intervention, your koi fish will not survive for long without a pump. Depending on the oxygen level in your pond or tank they will survive at least a day.

While it’s possible to have koi fish without a pump, it does take a lot of daily work to keep your fish healthy and happy.

Pumpless ponds or tanks should only be handled by people who have owned koi for over a decade, without that elevated level of experience you might just kill your koi.

Read further to learn what to do if your pump breaks, what your pump does for your koi fish, and the best pumps out there for your pond.

What a pond pump does for your koi

We have created an entire article with 3 reasons why pumps are vital for koi here. Here is the short answer:

The pump not only helps keep your pond or tank clean and oxygen-rich for your koi it also helps you with labor and stress. Not having a pump means that all of the benefits that it provides will have to be manually done.

That takes a lot of thought, care, and work on your part. To understand what to do if your pump breaks or if you want a koi pond without a pump you first need to understand what the pump does.

The pump provides two functions for koi, it cleans the pond from the toxins and excrement that the koi produce and it creates a current to generate oxygen in the pond for your koi to breathe.

Fish don’t have the luxury of disposing of their waste in designated areas and then moving away. It’s in the water with them. They have to swim in it, breathe it, and eat in it. In a bigger environment, they can get away, but in a 1000 gallon tank or pond, it’s not as easy.

These toxins, in turn, depletes the oxygen levels in the water making it harder for your koi to breathe. Adding to that crisis the koi needs additional oxygen to process their food properly.

They don’t have stomachs so all of their digestive processes happen in their intestines, causing them to need more time and oxygen to break down their food.

Due to the flow of water pumps also help combat invasive growths in your pond that compete with your koi for oxygen.

The process of eliminating waste by your pond pump limits the growth of algae. A little alga is ok, but it starts to cover the entire pond it hurts your koi.

In tiny amounts, the algae will eat the toxins that your koi naturally produce and also act as a little snack for your hungry carp. But unlike other pond plants who produce copious amounts of oxygen by absorbing the bad, algae will also absorb oxygen.

In massive amounts, it will take all of the oxygen from your koi. This especially becomes a problem in the spring and summer months known as algae bloom.

Algae bloom is caused by the direct sunlight, heat, and the waste in your koi’s water, whether that be from the koi themselves, uneaten food, or decaying matter.

These algae blooms are especially hard to combat when there is no filtration in the pond or if the water is still, or standing water. You can tell if you are having an algae issue by a pea-green looking carpet covering the top of your koi pond.

What to do if your pump breaks?

Your pump is going to break. That is just something that you are going to have to accept, it’s machinery and not meant to last for vast periods. Especially since your koi have a live span of 20-35 years.

Due to the importance of your pump to your koi’s livelihood checking it periodically is necessary. Without intervention, your koi will last a day, depending on the oxygen level in your pond or tank, if your pump breaks.

After that, you are playing a game with their life.

If your koi are not eating when they are not hibernating and seem lethargic then check the pump to make sure it is working properly.

Something to consider if your pump does break, your fish need more oxygen when they eat to digest their food. As soon as you know your pump is broken stop feeding them.

With the lack of oxygen already and the struggle it takes for them to reach the surface to breathe they are more likely to suffocate.

Once you discover that your pump is broken try to find a new pump immediately.

If you don’t have any local sources for a pump or the issue is due to a blackout there are a few things that you can do to keep them healthy until the power comes back on or you can get a new pump.

The main issue here is oxygen. A few hours after your pump is not working do a water change on the pond to circulate some oxygen through the water.

A 20 percent water change will do fine. You will have to do this several times, not skipping a day if it takes your pump longer to arrive.

For those who have issues with blackouts consider getting a backup generator if it is within your budget. It will save you a lot of time and effort along with the stress involved with desperately trying to keep your koi alive.

Ways to keep a koi pond without a pump

You can have a koi pond without a pump, but it will be a lot more work for you. If you are new to koi fish it’s best to start with the easiest option or you could kill your fish. Only seasoned koi owners need to try ponds without a pump.

Since koi are traditionally outside instead of an indoor system it is harder to keep the conditions right. A pond pump helps keep everything exactly right for your koi.

  • Plants
  • Put pond where there is no direct sunlight
  • Changing water

Plants are necessary for your koi pond even if you have a pump. They provide your fish with a place to hide from more aggressive members of the pond. They also absorb all of the toxins that naturally come from your koi.

In return, they put out oxygen which is essential to your koi not just to breathe, but also to digest their food. Another benefit is the competition for resources that plants provide in the pond.

With limited resources, plants will prevent algae growth because they absorb the same things.

Algae is a huge issue without a filtration system to combat it. While algae growth does happen with indoor tanks, it’s just a natural process when light, heat, and decay are combined in water, outdoors it’s harder to prevent.

To keep a koi pond without a pump you need to limit these factors to help prevent algae growth. Building your pond out of direct sunlight will help limit algae growth.

Putting the pond in the shade of trees or other structures limits the light that your pond will get and also helps with the heat during the steamier months.

Changing the water in your koi pond is essential especially if you don’t have a pump. Naturally, your pond is going to get dirty. From the koi processing their food to plants in the water dying and decaying to uneaten food to algae growth.

All of these things lead to depleting the pond of oxygen leaving your koi to suffocate on their waste. Something nobody wants to experience.

The pump cleans out of these nasty bits and puts more oxygen in the water, without that you will have to get rid of everything manually which is a time-consuming process. When changing the water concentrate on removing dead plants, food, and algae.

What to look for when getting a pump

If you are new to koi fish or honestly don’t have the time to change out the water every day then getting a pump is the best way to go. It will make your life much easier and you know that your beautiful koi are taken care of.

There are few things that you need to look for in a koi pond pump.

  • Size of pond
  • Amount of fish
  • Cost

The size of your pond needs to be considered. You don’t want to get a pump that is too small for the size of your pond or you will not get the results that you are looking for. It will not have the strength needed to circulate the water.

If you see that your koi are gasping for air, then your pond isn’t being cleaned properly and there is not enough oxygen in the water. It should have the strength to circulate your pond at least once per hour.

Due to their size, the koi needs a lot of space. Typically a pond fish they need at last 1000 gallon ponds that are three feet deep. Your pump needs to have enough pressure to accommodate this size.

Weaker pumps won’t have enough pressure for the size of your tank and only part of the water will be cleaned. If you have a 1000 gallon pond then you need a pump that has 500 GPH (gallons per hour).

Then it comes to the number of fish you have in your pond. If you have quite a few then you need to get a pump that works harder. With more fish, there is more waste in the water which means less oxygen for your fish.

Also, you want to create enough circulation for all of your fish to be able to breathe. Having multiple fish, and you will probably get more koi, the gallons per hour on your pump needs to be increased to 1000.

The cost of your pump doesn’t only mean the initial cost, but also how much it is to run. Your pump will be running for 24 hours a day with either a 1 hour or 2 hour circulation period.

3 great pumps for your koi pond

Finding an efficient pump that does not cost a lot to run will help you overall.

The Simple Deluxe pump (see it here) comes in two sizes with the option to purchase a 2 pack of the 1056 gph. This submersible pump at 1056 gph is perfect for a 1000 gallon tank that has multiple fish.

The front can be taken off for easy cleaning and it has both submersible and inline applications.

While not technically a pump this Sunnytech Solar Power Pond Oxygenator will be there for you if your pump ever fails or there is a power outage. It takes up to 10 hours to fully charge but will last up to 50 hours once it does.

For emergencies, you can use AA batteries. If your emergency is due to a blackout during a storm cover this with something durable like a table to prevent ruining the panel.

The Active Aqua Submersible Water Pump (see it here) has a large variety of GPH so if you have a smaller pond you can find the right one for you. It is also a smaller model than the Simple Deluxe above, but the top GPH is 1110.

While koi fish can survive in a pumpless pond it isn’t easy, both for your koi and for you as their caretaker. The pump makes life in the artificial environment of your man-made pond like home for your koi fish and that is the most important thing.

That they can live in ease. Koi fish already need a lot of care and consideration so give yourself a break and use a pump.

Leave a Comment