How Long Can Fish Go Without Food?

When you look at an adult koi fish, one of the first things you notice is probably how big they are. 

These fish can get absolutely huge and are incredible due to their visually striking nature. 

Needless to say, these fish eat a lot and need a large amount of food in order to grow to their full size and thrive. 

Sometimes though koi fish may decide not to eat or may not have access to food sources that are adequate. 

Let’s take a look at how long can fish go without food, including koi fish, and see if we can better understand the importance of having a regular fish feeding schedule.

The Importance of Proper Nutrition

Koi fish are naturally going to get rather large. While this is to be expected and certainly part of their charm, it is also something to consider in regard to their nutritional needs. 

They need to be able to store fat for the winter months where they may eat less and also need access to plenty of protein to support tissue growth over time, too. 

Koi fish are not picky eaters and will gobble up most things you offer to them with ease, so it may be tempting to feed them things like cheerios or other grain cereals, as this method of care has been popularized in recent years. 

Unfortunately, an excess of carbohydrates is considered not healthy for koi fish and actually poses significant health risks. 

There have been studies that have tied the over-consumption of bread and carbohydrates to the development of uncomfortable but benign fatty tumors within koi fish populations. 

These tumors are often harmless but can, over time, grow and contribute to larger health issues by limiting movement and become rather painful if they are abraded or bumped while the fish moves about within the pond. 

With so many good koi foods out there on a commercial scale that offer balanced nutritional levels, you can easily pick up a good that can keep your koi feeling full while offering them the opportunity to grow and thrive. 

Koi fish are enthusiastic eaters so offering a lot of good nutritional options will help ensure they are getting as much help as they can to reach the big, beautiful size we know and love.

how long can fish go without food

So, How Long Can Koi Fish Go Without Food?

When looking at how long can koi fish go without food, you have to understand that this is a question that varies greatly depending on the season at hand. 

Koi fish have metabolisms that speed up and slow down based on what the temperature is around them. 

This means that if it is cold outside, their metabolic processes slow down to accommodate for the temperature drop and allow them to survive without exerting as much energy. 

The koi will be less active and their bodies will be working hard to keep them alive by not expelling as much energy. 

During the winter months, koi can actually go for literal months without eating. 

Once the water temperature dips below an average of fifty two degrees fahrenheit, your koi’s metabolism begins to drop as well, resulting in the koi behaving in the aforementioned manner. 

Koi should actually not be fed when in this state since they need to have the lowered metabolic rate in order to survive during this time. 

During the summer months, koi can go around two weeks without eating. 

They have large stores of energy and can survive that long but do thrive under a regulated feeding schedule where they will have continual access to sources of food that provide balanced nutrition. 

For short periods of time, koi can survive off of the microorganisms and algae within the pond and their own body mass, but it is not a good idea to make it a regular habit for them to have to do so.  

During the summer and warmer months, koi fish will be doing most of their growing and need this food in order to be able to reach their proper size. 

Older koi fish that are larger will generally last longer under low nutrient conditions, while smaller koi will die off quickly. 

Babies and juveniles are especially susceptible to this type of issue and can become very sick very quickly, dying after even just a few days. 

In the event of an emergency where you have to leave your koi pond unattended and your koi unfed, arranging for someone to come and feed the fish as soon as they can is a good idea. 

If you cannot find someone and cannot be back within a few days, investing in a vacation feeder or slow release feeding block will be a great relief for your fish and provide them with sustenance even when you are not there to ensure they are fed. 

These conditions are not ideal and can still result in underfeeding and poor nutrition or overfeeding, which creates cloudy water and can contribute to bacterial overgrowth and illness, so you should not use these are regular feeding methods. 

They are suitable for emergencies and situations like vacations where you will not be present to feed, but are not a replacement for proper feeding and care measures and good husbandry. 

how long can fish go without food

Koi Count on You

Your koi fish rely on you to provide them with proper conditions for living. 

This is why having a good emergency plan in place can assist you in ensuring their care is delivered in an ongoing manner even if you are not home to ensure it. 

Have someone who is taught how to care for your koi ready to check in or appropriate short term feeding options available like feeding blocks or vacation feeders to ensure your koi have continued access to food. 

While koi can catch insects and eat algae, they need your help in order to get the nutrients they need. 

Have a plan at the ready and always be prepared and you should be just fine!