Hi everyone,
I inherited a pretty large pond 35 x 15 x 3.5 ft. six years ago. It's really established. It has a large filter, a waterfall for air which runs on a circular system with a satellite and several large water lillies. I have always had goldfish and small black carp along with newts, frogs, toads, snails and anything else you can think of.
I recently added a few Koi of various sizes, nothing huge, the largest was about 12 inches. They seem well really settled and happy, feeding well. I have also added about 50 small goldfish recently, in batches of 10 at a time.
Suddenly over the last week or so, the gold fish and black carp have started dying. Sometimes I find one a day or sometimes more, one horrid day I found 8. They have no fungus visible and in fact they look healthy, if you can say that about a dead fish!
I have tested the water and all marker including ammonia, nitrates, chlorine etc are good. Its not too hot in the UK. I guess if it was air then the larger fish would suffer first but they are really fine.
Could it be the food?
I wonder about insecticides from nearby farms?
Bacteria?
One thing I have noticed is that some of the goldfish seem to have lost their pigment. They started off a very bright orange but one or two have gone white. Not fungus, just white, like they have been washed.. That's odd isnt it?
Any suggestions would be welcome.
The pond is 10,000 gallons so I don't think i'm over stocked and I don't think I stocked too quickly.
I inherited a pretty large pond 35 x 15 x 3.5 ft. six years ago. It's really established. It has a large filter, a waterfall for air which runs on a circular system with a satellite and several large water lillies. I have always had goldfish and small black carp along with newts, frogs, toads, snails and anything else you can think of.
I recently added a few Koi of various sizes, nothing huge, the largest was about 12 inches. They seem well really settled and happy, feeding well. I have also added about 50 small goldfish recently, in batches of 10 at a time.
Suddenly over the last week or so, the gold fish and black carp have started dying. Sometimes I find one a day or sometimes more, one horrid day I found 8. They have no fungus visible and in fact they look healthy, if you can say that about a dead fish!
I have tested the water and all marker including ammonia, nitrates, chlorine etc are good. Its not too hot in the UK. I guess if it was air then the larger fish would suffer first but they are really fine.
Could it be the food?
I wonder about insecticides from nearby farms?
Bacteria?
One thing I have noticed is that some of the goldfish seem to have lost their pigment. They started off a very bright orange but one or two have gone white. Not fungus, just white, like they have been washed.. That's odd isnt it?
Any suggestions would be welcome.
The pond is 10,000 gallons so I don't think i'm over stocked and I don't think I stocked too quickly.