Help - My fish has a large swelling and is swimming upside down?

[pleasehelpme1]

Hello,

My fish has a large swelling near his posterior and is swimming upside down... presume it is the swim bladder... can you help?

I've tried salt and peas to flush his guts and relieve the constipation if that's what it is....

The other fish were avoiding him before I decided to isolated him and try the peas and salt etc

Is there a humane way to put him out of it's misery?

Thanks

 

[Sasha'Lou]

he is bloated. overfed. don't feed him for 2-3 days. happened with my fish