Please Help, Sick Balloon Molly

[jungleistmassiv]

Hi guys and girls

One of my balloon mollies is very ill. He was fine when we went out this morning, but only 2 hours leter later, he is swimming upside down, almost trying to right himself, but being unable to. He is gasping quite a lot, and looks pretty stressed. He has been showing no signs of illness previously.

Anyone have any ideas as to what could be wrong? I have had him just over a year now.

Thanks
Rich

 

[WILDER]

The fish is dying sorry remove to a container at the top of the tank.
Need to look at water stats in ammonia,nitrite,nitrate, and ph.
How many fish and which type.
Size of tank in gallons or litres.