I have about a 1000 gallon pond in my back yard. It used to have a bunch of goldfish and koi and natives in it 5 or 6 years ago until blue herons eradicated almost everything. Now there is not many goldfish or other fish as it is just too expensive to spend money on pricy fish that a bird is just going to eat when they can. Of the goldfish and few koi left in the pond I really started noticing several goldfish(but not koi) tended to die over the winter a few years ago, I would lose about 4-6 every year. I could not figure out why the lower populated pond was having so many goldfish die in winter, none really have signs of any disease, the ones that are dying I notice swim funny, go on their sides, and die. The pond had gravel in it and the pump was shut off when the temp is below 50 deg, there are some plants in it, it has a net over it in the winter so not many leaves on the bottom but every winter I seem to lose more and more goldfish.
Last year around fall a blue heron not only cleaned almost all the rest of the larger goldfish and koi out but knocked a large rock into the pond which sliced a big hole in the pond liner. After putting in a new pond liner I decided not to put gravel in it which I thought might be contributing to sludge/harboring bad bacteria. I put a bunch of larger feeder goldfish in the pond(not spending at the very least $6each on fish that is likely to get eaten before I make the pond blue heron safe) after isolating them for a week in a separate tub and treating them with a salt water mixture, of course a few feeders did not make it but the rest seemed healthy. They seemed to do fine the rest of the summer and fall but once again in the winter, particularly colder temps I am seeing and have to remove at least a dozen dead goldfish and 1 stoneroller so far. I lost 2 fancy goldfish only this year in our smaller front 100 gal pond but that is a first, the goldfish in that small pond never die where I lose 6-12 goldfish in the bigger pond every winter especially after it was stocked in lower numbers.
It can't be the gravel harboring dead spots/bad bacteria because I don't have any gravel now except for a few small trays on the bottom where I put plants. I vacuum the bottom of the pond in the fall before I put the net on, I don't feed them in the colder temps/winter. The ponds have been getting plenty of fresh rain. PH is around 7.5. Fish load is very small especially for the size of the pond, don't get it. Also don't get why I never lose koi, many say koi are harder and more delicate to take care of compared to goldfish but that is not my experience at all, I have never lost a koi from natural causes ever where I have lost dozens of goldfish in the same pond. My koi were never large.
Any ideas? Is it just normal to lose a half dozen to dozen smaller goldfish in the winter, our winters are not even that severe as we are in the South, temps in Dec/Jan/Fed are mostly in the upper 30's and 40's, pretty rare when it dips in the 20's for more then 2 or 3 days. Pond has only froze over once which only lasted a few days.
Last year around fall a blue heron not only cleaned almost all the rest of the larger goldfish and koi out but knocked a large rock into the pond which sliced a big hole in the pond liner. After putting in a new pond liner I decided not to put gravel in it which I thought might be contributing to sludge/harboring bad bacteria. I put a bunch of larger feeder goldfish in the pond(not spending at the very least $6each on fish that is likely to get eaten before I make the pond blue heron safe) after isolating them for a week in a separate tub and treating them with a salt water mixture, of course a few feeders did not make it but the rest seemed healthy. They seemed to do fine the rest of the summer and fall but once again in the winter, particularly colder temps I am seeing and have to remove at least a dozen dead goldfish and 1 stoneroller so far. I lost 2 fancy goldfish only this year in our smaller front 100 gal pond but that is a first, the goldfish in that small pond never die where I lose 6-12 goldfish in the bigger pond every winter especially after it was stocked in lower numbers.
It can't be the gravel harboring dead spots/bad bacteria because I don't have any gravel now except for a few small trays on the bottom where I put plants. I vacuum the bottom of the pond in the fall before I put the net on, I don't feed them in the colder temps/winter. The ponds have been getting plenty of fresh rain. PH is around 7.5. Fish load is very small especially for the size of the pond, don't get it. Also don't get why I never lose koi, many say koi are harder and more delicate to take care of compared to goldfish but that is not my experience at all, I have never lost a koi from natural causes ever where I have lost dozens of goldfish in the same pond. My koi were never large.
Any ideas? Is it just normal to lose a half dozen to dozen smaller goldfish in the winter, our winters are not even that severe as we are in the South, temps in Dec/Jan/Fed are mostly in the upper 30's and 40's, pretty rare when it dips in the 20's for more then 2 or 3 days. Pond has only froze over once which only lasted a few days.