Golden Wonder killifish suffering

[Bobby5355]

I hope someone can help me. I have had a golden Wonder for about a year now. He got too big and aggressive for my tank so I gave him to the local pet store. They put him in a tank with other fish and said that these fish were also given to the store and they are not to be sold. I checked on the fish a couple days later and noticed he had some fin missing so I took him back home and gave him a tank of his own I siphoned water out of my good tank to make up the new one. The next day I noticed him bobbing and listing at the bottom of the tank his belly is really swollen and this started 4 days ago. I immediately started to raise the temp to 80 degrees and put him in a mesh basket so the filter would not suck him in. Noticed he was beat up more than I thought I added some aquarium salt. On day three I fed him some frozen peas I had cooked and skinned he ate a little but not much and is still upside down. He still has some spunk in him as I try to feed him he wiggled away so I stopped. How long can I keep the water at 80 degrees? Does anyone know how long this might last or am I just throwing my money away. Any help would be appreciated thank you

 

[Colin_T]

can you post a picture and a short 20 second video of the fish?
put the video on youtube and copy & paste the link here.
set you cameras resolution to its lowest setting so the image fits on this website.