Tropical Fish Forums

[Buttercup]

Our koi acted aggressive toward other fish, she ate a small algae eater and bullied another larger one. She would jump in the tank and literally hit the top of it.. last night she was dead. What is this? The water tested OK.. I have another tank with two kois, they are mellow like she was when we got her. Do they get more aggressive and wild as they get bigger?? The reason we did not put her in a koi pond was that we thought she would jump out out it.

[diademhill]

What were the water test readings please?

[Maestro]

Also, how large is the tank that the Koi are kept in?
_________________
2500 gallon (9,450 L) Koi Pond
15 gallon (57 L) Low-light planted
6 gallon (23 L) Betta splendens

[Buttercup]

I took a water sample into the fish store and they said everything was fine... I did not ask for more than this. We had her in a 30 gallon tank by herself for the first year, brought in a newbie and it was dead within a day. Then she ate the algae eater, so I was told to get a pleco and she bullied it to near death, we moved it to another tank but it died within 2 days. She was acting so weird... jumping around the tank and hitting the top, definitely distressed but I did not know why since we moved everyone out of her tank. She was fine at 2 am when my husband came home from work.. turned off her light and I woke up at 3 am, she was dead. We are heartbroken and not sure what went wrong

[diademhill]

Did the store use a dip strip?
The multi test strips don't test for ammonia.

The koi's behaviour suggests toxins in the water and as 1000 gallons is the recommended pond size for the first koi I hope you realise how inadequate 30 gallons is - like a goldfish bowl.

[Buttercup]

The pet store did use the strips, and gave us a sheet showing all categories of the water were in the healthy range.

Buttercup was given to us in a bowl, they had a huge koi pond but she was so little, they were afraid she would get eaten. The next day took her into the fish store and we came home with the tank after being told she was a koi and would get big but would be more then fine in this for a few years. She was 3-4 inches. The kois we have now are at most 2 inches.

[diademhill]

Please measure your tank and your other fish. Strips don't test for ammonia and I suspect that is the culprit.
Koi in my pond grow to over 8" in one year so a 3-4 inch fish older than this is severely stunted.
Koi really don't belong in tanks.

[Cliff Mayes]

The Japanese breeders get 3' fish in just 2 or 3 years by culling ruthlessly and feeding lots of food to a few fish in a mud bottomed, large, pond. KOI are quite capable of phenomenal growth under good conditions, which they do not see in small ponds and tanks. Most animals must grow quickly or they do not survive in the wild. The fancy colored carp we fancy are very artificial (as far a color and to some degree shape) but they still hue to the normal routines of their wild brethren.

It bears repeating...tanks are not natural in size or what we try to do with them and animals are not human and the health both physical and mental are not the same as humans.

Sorry but the last paragraph was egregious and was not meant for you.
_________________
wirehair

[Buttercup]

I appreciate all the comments and wish I had joined a site such as this one back when I was first given her. My sister in law's family has a huge koi pond so I can give my litte ones to them where they can thrive. Thanks everyone

[katienaha]

terribly sorry you had to experience this the hard way, and that your fish had to die. Definetly re-home those other ones, they will thank you for it by creating many more offspring
_________________
Let the current take you where you may not always want to go.