Fish starts swimming upside down before my eyes

[DFT]

I just got two northern sucker for my tank one was swimming around normal and suddenly went in to a corner tail up and stayed there I removed him with a net and he went belly up but was still alive I don't think this is swim bladder the tank is 20 gallon with good PH and good ammonia nitrate and nitrite levels.

The fish were acclimated but the one that went belly up had a red nose from overcrowding from where I got him.

 

[Autumnsky]

Can you change out the red nosed one for a better/healthier one.

Did you see the person catch the fish, it sounds by the damage to its nose, possible it was scared and ran into the glass maybe while being captured.

In the future, do not accept an injured or ill looking fish. Skip the fish if they are in poor conditions.

Best hope would be for you to keep up regular pwc and provide good healthy food for the fish in hopes it can recover from poor conditions. And heal as quickly as possible from its injury.

Is this the fish
https://en.wikipedia.org/wiki/Northern_hogsucker

What size tank are these going to be living soon - if this is it they get big fairly quickly and 20G won't be big enough for long?

 

[DFT]

Can you change out the red nosed one for a better/healthier one.

Did you see the person catch the fish, it sounds by the damage to its nose, possible it was scared and ran into the glass maybe while being captured.

In the future, do not accept an injured or ill looking fish. Skip the fish if they are in poor conditions.

Best hope would be for you to keep up regular pwc and provide good healthy food for the fish in hopes it can recover from poor conditions. And heal as quickly as possible from its injury.

Is this the fish
https://en.wikipedia.org/wiki/Northern_hogsucker

What size tank are these going to be living soon - if this is it they get big fairly quickly and 20G won't be big enough for long?

We rescued them from a bait distributor where I know they can get injured the other one has a small wound on the fin so I will be more careful next time.

And to answer your question about what to do with it when it gets too big we have a backyard pond that is able to be wintered

 

[Autumnsky]

Ah, that makes sense.

Keep your water quality very good. If you haven't yet do a couple pwc. As a baseline, and monitor the water parameters and if any of the numbers are not excellent, do a pwc. This will relieve that possibility of stress on their systems, giving them the best possible chance at healing.