Guys I need help for my ID shark

[Sambit1711]

Recently I made a huge 350+ gallon tank for my Japanese koi and 3 ID shark .. but one of them couldn't resist the water change or something and developed cloudy eye. ( I added the filtration system after few days ) . I took him out into my hospital tank and have been treating him since 7 days. What I did
Daily 50% water change
Good antibacterial medicine
And aquarium salt
Still my shark is not recovering adding to that I think his eyes are falling out . Iam freaking out

 

[thebiggerthebetter]

Welcome to the MFK!

What do you mean by adding the filtration after several days?

Whenever anything goes wrong with the fish we keep, the first thing to do is to test water for ammonia and nitrite by a reputable liquid test kit, not dip sticks.

 

[Sambit1711]

Welcome to the MFK!

What do you mean by adding the filtration after several days?

Whenever anything goes wrong with the fish we keep, the first thing to do is to test water for ammonia and nitrite by a reputable liquid test kit, not dip sticks.

I did for the main tank and fish had been transferred to the hospital tank. Any suggestions what should I do?

 

[thebiggerthebetter]

I am trying to understand if and why you'd keep the fish in an unfiltered tank for several days because it would likely sicken them or even kill them. I don't know your level of experience or knowledge in the hobby. At the face value I'd assume that you need to learn what nitrogen cycle is in a fish tank but perhaps I am wrong and you know all this already.

Sorry. I thought I have provided the first step to do. Please get the test kit, learn and do the testing. You won't get around without this kit, if you chose to believe me, which I don't expect.

The tests are not expensive, relatively speaking, around $20 for hundreds of tests, many years, e.g., https://www.chewy.com/api-freshwate...eU50puSTMNid3XdHoUCSYQ1DO83X7_vBoC2bsQAvD_BwE

 

[Fishman Dave]

Hi Sambit, welcome to MFK.
Keeping ID shark with koi will be tricky generally as koi are quite active and skittish when in tanks, which is the exact kind of fish to set off the shark. To keep koi anyway I guess your filtration would be pretty substantial, especially in a tank with no plants to assist. As Victor mentions, knowing the readings of ph, nitrate, nitrite and ammonia are essential to make any diagnosis and are really useful when transferring fish from tank to tank.
However, one point to note, you will really struggle to make a (what looks like) 10” ID shark settle and be happy in a 2x1x1 tank, and if the fish is not settled and happy, it will always be stressed and not recovering. Unfortunately IMO you will need a larger container of water, doesn’t have to be a glass tank, but something twice the size or bigger than the tank ( where did the fish move from?).
The shark has obvious signs of stress, from the cloudy eyes to the nose damage often from constant rubbing in smaller accommodation.
IMO it might have been best to have left the shark in the 350g but without the readings we cannot really say what the cause and hence remedy is.