Cory Death

[Haveagojoe]

Iv'e six peppered corys and got up this morning to find one upside down on the surface dead I thought,went to get the net to fish him out and he swam back down,but after watching him for a bit it seemed obvious that he was unwell, he couldn't stay on the bottom at all kept floating to the top of the tank and turning upside and staying motionless,this went on for a couple of hours and it seemed kinder to put him out his mysery quickly,now it looks like another one is starting to show the same syptoms, they have been in tank about 3 months now without any other fish or plants being added, any ideas anyone.

 

[WILDER]

How many gallons or litres is the tank.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.
What do you feed the fish.

Do the corys look bloated.
Can they maintain balance in the water.
Any red streaking or sores on there bodies.
Do they look pale or darker in colour.
Do the corys act listless and lethagic.
What do there barbels look like.