We have kept fish for years Koi's mainly but also have some senior goldfish. Our current natural pond is up to 3 mtrs deep 7 wide and 15 long approx 85000-100000 litres of water. 24 hour filtration system and skimmer, nets to keep birds out.
The pond is not over stocked water is regularily checked and when fish have any sign of infection etc we know how to mediacte and / or call the vet to look.
This winter all the goldfish died 100+ no signs of fungus wounds etc. The koois are healthy and active, water has been tested was ok. Winter was cold pond did freeze over for a few days but previous years winters have been more extreme for longer period. In 25 years with different sized ponds we have never lost so many fish, in a normal year you can expect to loose a couple due to old age etc but nothing on this scale.
The only thing I can think of is sudden change in water temperature one day the outside air temperature increased by 11 degrees ice melted and then following day partially re froze.
A small number of goldfish survived a couple of days longer but they also later died.
Anyone any ideas. Tks Peter
The pond is not over stocked water is regularily checked and when fish have any sign of infection etc we know how to mediacte and / or call the vet to look.
This winter all the goldfish died 100+ no signs of fungus wounds etc. The koois are healthy and active, water has been tested was ok. Winter was cold pond did freeze over for a few days but previous years winters have been more extreme for longer period. In 25 years with different sized ponds we have never lost so many fish, in a normal year you can expect to loose a couple due to old age etc but nothing on this scale.
The only thing I can think of is sudden change in water temperature one day the outside air temperature increased by 11 degrees ice melted and then following day partially re froze.
A small number of goldfish survived a couple of days longer but they also later died.
Anyone any ideas. Tks Peter
