My Koi is trying to Jump out of water, why?

manishr78

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Hey,

I would like to request assistance regarding another incident. I have observed my Koi attempting to leap out of the aquarium on several occasions. Initially, my tank was open at the top, but there was an incident where the Koi successfully jumped out. Fortunately, I was able to return him to the water promptly, and he survived. Subsequently, I had no choice but to cover the tank, yet I remain uncertain about the reasons behind his jumping behavior. What might have caused this issue?
 
Koi have a torpedo shaped body which tells us that they need space. In general, a fishtank is not big enough to keep them their whole life in. Koi are fast growing fish. So, at some point they need to be in a bigger body of water like a pond. If they don't have enough space in their environment, they can jump. Even when a pond is too small for them, they'll try to jump. Especially when they make speed.
Kept and bred koi for 20 years to know this.
 
In my experience Koi and goldfish that want to escape too much of a tank are nearly always related to poor water quality.

Do you have a master test kit ? How are the ammonia and nitrite readings in the tank ? What is the water temperature ?
 
I'm with Malok on this.

When does the fish try to jump out?
Whenever you go near it, when you turn the light on?

Check your water quality for ammonia, nitrite, nitrate and pH. Post the results in numbers here.

Check the temperature. Koi carp are cold water fish and if the water is warm (highly probable in India), then the oxygen level will be lower and the fish will be more stressed. Make sure there's lots of aeration/ surface turbulence to maximise the oxygen in the water.

Post a picture of the tank so we can see how big the fish is compared to the tank.

Does the aquarium have a light above it?
If yes, how do you turn the light on?

--------------------

TURNING LIGHTS ON AND OFF
Stress from tank lights coming on when the room is dark can be an issue. Fish don't have eyelids and don't tolerate going from complete dark to bright light (or vice versa) instantly.

In the morning open the curtains or turn the room light on at least 30 minutes (or more) before turning the tank light on. This will reduce the stress on the fish and they won't go from a dark tank to a bright tank instantly.

At night turn the room light on and then turn the tank light off. Wait at least 30 minutes (or more) before turning the room light out. This allows the fish to settle down for the night instead of going from a brightly lit tank to complete darkness instantly.

Try to have the lights on at the same time each day. Use a timer if possible.

If the light unit is programmable, have it on a low setting for the first 30-60 minutes and increase the brightness over time. Do the opposite in the evening and gradually reduce the light for the last 30-60 minutes before lights out.

If you don't have live plants in the tank, you only need the light on for a few hours in the evening. You might turn them on at 4 or 5pm and off at 9pm.

If you do have live plants in the tank, you can have the lights on for 8-16 hours a day but the fish and plants need 8 hours of darkness to rest. Most people with live plants in their aquarium will have the lights on for 8-12 hours a day.
 
According to the OP's other thread, this 35 litre/9 gallon tank contains 4 angelfish, 1 koi and 1 honey gourami. It is grossly overstocked and the water conditions may be far from perfect.


I maintain a 35-liter aquarium that houses four angelfish, one honey gourami, and one koi. I have some concerns regarding water changes. I typically perform a 30-40% water change each week; however, this week I observed that the water had become excessively cloudy, despite the filter operating effectively with appropriate biological media.
 
I'm with Malok on this.

When does the fish try to jump out?
generally observed he tried jumping out at night when the lights completely goes off
Whenever you go near it, when you turn the light on?

Check your water quality for ammonia, nitrite, nitrate and pH. Post the results in numbers here.
Water quality was good No ammonia however slight nitrate
Check the temperature. Koi carp are cold water fish and if the water is warm (highly probable in India), then the oxygen level will be lower and the fish will be more stressed. Make sure there's lots of aeration/ surface turbulence to maximise the oxygen in the water.
Temperature is around 29-30c
Post a picture of the tank so we can see how big the fish is compared to the tank.

Does the aquarium have a light above it?
If yes, how do you turn the light on?

--------------------

TURNING LIGHTS ON AND OFF
Stress from tank lights coming on when the room is dark can be an issue. Fish don't have eyelids and don't tolerate going from complete dark to bright light (or vice versa) instantly.

In the morning open the curtains or turn the room light on at least 30 minutes (or more) before turning the tank light on. This will reduce the stress on the fish and they won't go from a dark tank to a bright tank instantly.

At night turn the room light on and then turn the tank light off. Wait at least 30 minutes (or more) before turning the room light out. This allows the fish to settle down for the night instead of going from a brightly lit tank to complete darkness instantly.

Try to have the lights on at the same time each day. Use a timer if possible.

If the light unit is programmable, have it on a low setting for the first 30-60 minutes and increase the brightness over time. Do the opposite in the evening and gradually reduce the light for the last 30-60 minutes before lights out.

If you don't have live plants in the tank, you only need the light on for a few hours in the evening. You might turn them on at 4 or 5pm and off at 9pm.

If you do have live plants in the tank, you can have the lights on for 8-16 hours a day but the fish and plants need 8 hours of darkness to rest. Most people with live plants in their aquarium will have the lights on for 8-12 hours a day.
Well I replied to your post inline
 
generally observed he tried jumping out at night when the lights completely goes off

Water quality was good No ammonia however slight nitrate

Temperature is around 29-30c

Well I replied to your post inline
What test kit are you using? With how overstocked this tank is I'm struggling to believe you have no ammonia at all.
 
Following the community's recommendation, I promptly acquired an additional 1ft x 1ft tank, which I have equipped with a hang-on-back filter. I transferred some bio-media from my current setup and relocated all four of my angelfish to this new tank. The water in the new tank consists of a combination of existing water from my old tank and freshly dechlorinated water, to which I have added 1 gram of nitrifying bacteria from Aquavitals
 
What test kit are you using? With how overstocked this tank is I'm struggling to believe you have no ammonia at all.
I am using this kit for measuring my water parameter

Qpets® 50pcs Water Testing PH Testing Strips, 14 in 1 Water Testing Kit Aquarium Test Strips Professional Freshwater Water Testing Kit for PH GH&KH Nitrite Nitrate Chlorine Carbonate​

 
I am using this kit for measuring my water parameter

Qpets® 50pcs Water Testing PH Testing Strips, 14 in 1 Water Testing Kit Aquarium Test Strips Professional Freshwater Water Testing Kit for PH GH&KH Nitrite Nitrate Chlorine Carbonate​

Strips are not very accurate unfortunately, and with the amount of fish you have it is highly likely you have levels of ammonia and nitrite at least. You need to be doing very very large daily water changes with this amount of fish, but long term this just isn't sustainable. You really need to rehome these fish or get a larger tank for their sake, I can't stress this enough.
 
It might just be as simple, as the tank is too warm for comfort for the Koi... angel fish, & Koi, have very different temperature parameters...

also maybe the angels are getting a bit nippy or bossy ( they do, do that ) with the koi, & he's just trying to get away
 
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Following the community's recommendation, I promptly acquired an additional 1ft x 1ft tank, which I have equipped with a hang-on-back filter. I transferred some bio-media from my current setup and relocated all four of my angelfish to this new tank. The water in the new tank consists of a combination of existing water from my old tank and freshly dechlorinated water, to which I have added 1 gram of nitrifying bacteria from Aquavitals
Please, please, please listen to what everyone in this thread is saying and return the fish and obtain something more suitable to your tanks. I’m sure you’re not deliberately trying to be cruel and want to do the best for the fish in your care but it’s so upsetting to hear what you’re putting your fish through.
Please listen and do what’s best for them.
 

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