Mystery behind death of my koi

[neha]

I had two koi fishes in aquarium tank, one of which died a few days ago.
The fish had shown the signs of swim bladder disease approximately two weeks before she died. But fortunately she was cured at that time because of the peas which I gave her to eat and that time i had also put her in a separate tank with antibacterial medicine.
But suddenly few days ago she showed similar signs again but this time it was the worst. She started tilting towards her left side and would even turn upside down and finally land on gravels.
I had noticed something unusual near her left pectoral fin . But it was too small that i thought it to be normal though it was not there on right pectoral fin.
She was eating like any other normal fish even at this time.
I had again put her in separate quarantine tank with antibacterial medicine and anti parasitic medicine (as suggested by aquarium store)But she didn't show any positive signs. She would just stay near filter and that too in a very wierd position that is mouth downwards just a little above the gravels and the tail towards upside and the whole body sticking near the filter.
I had read that epsom salt helps in swim bladder so thinking that she might be having the disease again I had put 15 grams of epsom salt in 25 liter tank.
After half an hour she didn't show any sign of living.

What could be the reason behind her death?
I have given a photo of her ( kept in a tub to get photo clearly and easily)

Any advice would be
appreciated

 

[JRS]

Sorry for the loss of your fish. Given good water conditions, it is extremely hard to say for sure without a pathology of the diseased tissues. Sometimes medicine seems to knock down a pathogen for awhile without eliminating it but the bug returns once the medicine is gone. Some similar symptoms can be caused by different diseases with different treatments. My metric math lookup comes out to 3.6 teaspoons of salt per 6.6 gallons of water? Perhaps in an already weakened fish it might of been the last straw but I suspect your fish would have passed anyway. Sounds like you tried your best; which is all you can do.

Vet's salt info:

 

[Phaewryn]

I had two koi fishes in aquarium tank, one of which died a few days ago.
15 grams of epsom salt in 25 liter tank.

Koi are not aquarium fish, and don't do well in them, from what I've read. How big was the aquarium and how big were the fish? Not that it matters now, but it may be that koi are not the fish for your needs and knowing that might save you some grief later. That doesn't seem like a too strong of dose for epsom salt, but abrupt shifts in pH levels can kill fish. I'm American so don't have a good grasp of metric measurements. That's what, a 5 gallon tank or so, and about two and a half teaspoons of epsom salt? Did you add it all at once or slowly adding a little over a period of a couple days? It could be that it shocked the fish and killed it if you added it all at once. It's usually better to stick to the medications the fish store recommends rather than trying things from the internet, but like JRS noted, it sounds like the fish was going to die anyway. The best thing you can do is learn from the experience. Figure out what you did wrong (if anything) and try not to make it again. Keeping koi in aquariums is not usually advised. It is likely that the fish were crowded and living in poor water conditions due to that. If you still have the aquarium set up and plan to get more fish (or have other fish in it) I would immediately get a good testing kit and be sure the water conditions are good. Then try to get fish that are appropriate for the size tank you have. Unless it's a huge aquarium, it's likely too small for koi.

 

[neha]

Sorry for the loss of your fish. Given good water conditions, it is extremely hard to say for sure without a pathology of the diseased tissues. Sometimes medicine seems to knock down a pathogen for awhile without eliminating it but the bug returns once the medicine is gone. Some similar symptoms can be caused by different diseases with different treatments. My metric math lookup comes out to 3.6 teaspoons of salt per 6.6 gallons of water? Perhaps in an already weakened fish it might of been the last straw but I suspect your fish would have passed anyway. Sounds like you tried your best; which is all you can do.

Vet's salt info:

Thank you so much for your reply

 

[neha]

Koi are not aquarium fish, and don't do well in them, from what I've read. How big was the aquarium and how big were the fish? Not that it matters now, but it may be that koi are not the fish for your needs and knowing that might save you some grief later. That doesn't seem like a too strong of dose for epsom salt, but abrupt shifts in pH levels can kill fish. I'm American so don't have a good grasp of metric measurements. That's what, a 5 gallon tank or so, and about two and a half teaspoons of epsom salt? Did you add it all at once or slowly adding a little over a period of a couple days? It could be that it shocked the fish and killed it if you added it all at once. It's usually better to stick to the medications the fish store recommends rather than trying things from the internet, but like JRS noted, it sounds like the fish was going to die anyway. The best thing you can do is learn from the experience. Figure out what you did wrong (if anything) and try not to make it again. Keeping koi in aquariums is not usually advised. It is likely that the fish were crowded and living in poor water conditions due to that. If you still have the aquarium set up and plan to get more fish (or have other fish in it) I would immediately get a good testing kit and be sure the water conditions are good. Then try to get fish that are appropriate for the size tank you have. Unless it's a huge aquarium, it's likely too small for koi.

Thank you so much for your reply